These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Anechoic chamber qualification at ultrasonic frequencies  

NASA Astrophysics Data System (ADS)

Qualifying an anechoic chamber for frequencies that extend into the ultrasonic range is necessary for research work involving airborne ultrasonic sound. For example, an anechoic chamber allows for measurements of the direct sound radiated by an object without reflections from walls. The ANSI S12.55/ISO 3745 standard which covers anechoic chamber qualification does not extend into the ultrasonic frequency range, nor have others discussed this frequency range in the literature. An increasing number of technologies are employing ultrasound; hence the need to develop facilities to conduct basic research studies on airborne ultrasound. This presentation will discuss the challenges associated with chamber qualification and present the results for qualification of a chamber at Brigham Young University. [This work has been funded by the Los Alamos National Laboratory

Jenny, Trevor; Anderson, Brian

2010-10-01

2

Almond test body. [for microwave anechoic chambers  

NASA Technical Reports Server (NTRS)

The invention is an almond shaped test body for use in measuring the performance characteristics of microwave anechoic chambers and for use as a support for components undergoing radar cross-section measurements. The novel aspect of this invention is its shape, which produces a large dynamic scattered field over large angular regions making the almond valuable for verifying the performance of microwave anechoic chambers. As a component mount, the almond exhibits a low return that does not perturb the measurement of the component and it simulates the backscatter characteristics of the component as if over an infinite ground plane.

Dominek, Allen K. (inventor); Wood, Richard M. (inventor); Gilreath, Melvin C. (inventor)

1989-01-01

3

Characteristics of an anechoic chamber for fan noise testing  

NASA Technical Reports Server (NTRS)

Acoustical and mechanical design features of NASA Lewis Research Center's engine fan noise facility are described. Acoustic evaluation of the chamber, which is lined with an array of stepped wedges, is described. Results from the evaluation in terms of cut-off frequency and non-anechoic areas near the walls are detailed. Fan models are electrically driven to 20,600 RPM in either the inlet mode or exhaust mode to facilitate study of both fore and aft fan noise. Inlet noise characteristics of the first fan tested are discussed and compared to full-scale levels. Turbulence properties of the inlet flow and acoustic results are compared with and without a turbulence reducing screen over the fan inlet.

Wuzyniak, J. A.; Shaw, L. M.; Essary, J. D.

1977-01-01

4

Apparent distance of sounds recorded in echoic and anechoic chambers  

Microsoft Academic Search

With miniature microphones inserted into the external ear canals of a model and the sound source 90° to left of midline, low-pass, and high-pass, broadband noise bursts were picked up and recorded on magnetic tape. The bursts were generated in 2 highly contrasting acoustic environments: an anechoic and an echoic chamber. The taped sounds were played back monaurally and binaurally

Robert A. Butler; Elena T. Levy; William D. Neff

1980-01-01

5

Design and characterization of an anechoic aeroacoustic facility  

NASA Astrophysics Data System (ADS)

The design and characterization of an anechoic wind tunnel facility at the University of Florida are presented. A previously existing and ISO 3745 validated 100-Hz anechoic chamber is upgraded to incorporate an open-jet anechoic wind tunnel facility suitable for airframe noise studies, including swept-wing trailing edge studies. For suitable modeling of landing conditions, a chord-based Reynolds number of 3 to 4 million is required. The wind tunnel is driven by a 224-kW centrifugal fan controlled by a variable frequency drive. The test section measures 0.74 m (29) by 1.12 m (44) by 1.83 m (6 ft). The estimated maximum velocity attainable in the test section is ~ 76 m/s (250 ft/s). Preliminary measurements at 17 m/s indicate excellent flow uniformity and a turbulence intensity of 0.11%. Background noise level measurements with an empty test section reveal an overall SPL from 100 Hz 20 kHz of 49.9 dB, with a peak 1/3 octave-band level of 46 dB at 100 Hz that decreases to 29.9 dB at 1 kHz. Facility characterization experiments over a range of test section speeds are also reported, along with the results of preliminary trailing edge noise experiments.

Mathew, Jose; Bahr, Chris; Carroll, Bruce; Sheplak, Mark; Cattafesta, Lou

2005-09-01

6

Analysis of Anechoic Chamber Testing of the Hurricane Imaging Radiometer  

NASA Technical Reports Server (NTRS)

The Hurricane Imaging Radiometer System (HIRAD) is a new airborne passive microwave remote sensor developed to observe hurricanes. HIRAD incorporates synthetic thinned array radiometry technology, which use Fourier synthesis to reconstruct images from an array of correlated antenna elements. The HIRAD system response to a point emitter has been measured in an anechoic chamber. With this data, a Fourier inversion image reconstruction algorithm has been developed. Performance analysis of the apparatus is presented, along with an overview of the image reconstruction algorithm

Fenigstein, David; Ruf, Chris; James, Mark; Simmons, David; Miller, Timothy; Buckley, Courtney

2010-01-01

7

A two dimensional finite difference time domain analysis of the quiet zone fields of an anechoic chamber  

Microsoft Academic Search

Prediction of anechoic chamber performance is a difficult problem. Electromagnetic anechoic chambers exist for a wide range of frequencies but are typically very large when measured in wavelengths. Three dimensional finite difference time domain (FDTD) modeling of anechoic chambers is possible with current computers but at frequencies lower than most chamber design frequencies. However, two dimensional FDTD (2D-FTD) modeling enables

Deirdre A. Ryan; Raymond J. Luebbers; Truong X. Nguyen; Karl S. Kunz; David J. Steich

1992-01-01

8

A two dimensional finite difference time domain analysis of the quiet zone fields of an anechoic chamber  

NASA Technical Reports Server (NTRS)

Prediction of anechoic chamber performance is a difficult problem. Electromagnetic anechoic chambers exist for a wide range of frequencies but are typically very large when measured in wavelengths. Three dimensional finite difference time domain (FDTD) modeling of anechoic chambers is possible with current computers but at frequencies lower than most chamber design frequencies. However, two dimensional FDTD (2D-FTD) modeling enables much greater detail at higher frequencies and offers significant insight into compact anechoic chamber design and performance. A major subsystem of an anechoic chamber for which computational electromagnetic analyses exist is the reflector. First, an analysis of the quiet zone fields of a low frequency anechoic chamber produced by a uniform source and a reflector in two dimensions using the FDTD method is presented. The 2D-FDTD results are compared with results from a three dimensional corrected physical optics calculation and show good agreement. Next, a directional source is substituted for the uniform radiator. Finally, a two dimensional anechoic chamber geometry, including absorbing materials, is considered, and the 2D-FDTD results for these geometries appear reasonable.

Ryan, Deirdre A.; Luebbers, Raymond J.; Nguyen, Truong X.; Kunz, Karl S.; Steich, David J.

1992-01-01

9

An open-boundary quad-ridged guide horn antenna for use as a source in antenna pattern measurement anechoic chambers  

Microsoft Academic Search

The present paper introduces a new antenna design to be used in anechoic chambers. When measuring three-dimensional patterns, the receiving antenna in the anechoic chamber must be able to sense the two orthogonal components of the field that exist in the far field. This can be accomplished by mechanically rotating the source horn in the chamber. A better and faster

Vicente Rodriguez

2006-01-01

10

ATS 6 EMI field measurements techniques and results. [anechoic chamber scale model testing  

NASA Technical Reports Server (NTRS)

At the present time 'Applications Technology Satellite (ATS)-6' is the world's largest communication satellite. It handles telecommunications in the frequency range of 40 - 30,000 MHz. Power levels on board the spacecraft range from -110 dBm to 52.5 dBw. Consequently considerable care was required in the design and test of this spacecraft, in order to provide assurances that the spacecraft would perform properly in its own RF environments. The testing was performed first by placing the earth viewing module (EVM) in a specially constructed 'small' anechoic chamber with an overhead parabolic reflector section, of 8' in diameter, instead of the 30' reflector of the full scale design. The near field analysis of this paper proves that this test configuration leads to a desirable overtest for the spacecraft. The test requirements, procedure and results are also explained.

Afifi, M. S.; Keiser, B. E.

1974-01-01

11

A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber  

NASA Astrophysics Data System (ADS)

Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.

Chiang, W. Y.; Wu, M. H.; Wu, K. L.; Lin, M. H.; Teng, H. H.; Tsai, Y. F.; Ko, C. C.; Yang, E. C.; Jiang, J. A.; Barnett, L. R.; Chu, K. R.

2014-08-01

12

Calibration of the Ames Anechoic Facility. Phase 1: Short range plan  

NASA Technical Reports Server (NTRS)

A calibration was made of the acoustic and aerodynamic characteristics of a small, open-jet wind tunnel in an anechoic room. The jet nozzle was 102 mm diameter and was operated subsonically. The anechoic-room dimensions were 7.6 m by 5.5 m by 3.4 m high (wedge tip to wedge tip). Noise contours in the chamber were determined by various jet speeds and exhaust collector positions. The optimum nozzle/collector separation from an acoustic standpoint was 2.1 m. Jet velocity profiles and turbulence levels were measured using pressure probes and hot wires. The jet was found to be symmetric, with no unusual characteristics. The turbulence measurements were hampered by oil mist contamination of the airflow.

Hickey, D.; Soderman, P. T.; Karamcheti, K.; Koutsoyannis, S. P.; Hopkins, R.; Mclachlan, B.

1980-01-01

13

Effectiveness of an inlet flow turbulence control device to simulate flight noise fan in an anechoic chamber  

Microsoft Academic Search

A hemispherical inlet flow control device was tested on a 50.8 cm. (20-inch) diameter fan stage in the NASA-Lewis anechoic chamber. The control device used honeycomb and wire mesh to reduce turbulence intensities entering the fan. Far field acoustic power level results show about a 5 db reduction in blade passing tone and about 10 dB reduction in multiple pure

R. P. Woodward; J. A. Wazyniak; L. M. Shaw; M. J. MacKinnon

1977-01-01

14

Investigation on High Performance of 10m Semi Anechoic Chamber by using Open-Top Hollow Pyramidal Hybrid EM Wave Absorber  

NASA Astrophysics Data System (ADS)

The emission radiated from electric and electronic equipments is evaluated through OATS. Recently, it is not fully prepared the environment for OATS because of a variety of communication radiation sources (e.g., digital television broadcast and cellular phone station). Therefore, the EM anechoic chambers are becoming more and more important as EMI test site. On the other hand, the EM anechoic chambers are needed high performance in order to cut down EMI countermeasure cost and calculate the antenna factor. The objective of this paper is mainly to present the EM wave absorber design in order to obtain within ±2dB against the theoretical site attenuation values in the 10m semi anechoic chamber at 30MHz to 300MHz. We get the necessary reflectivity of EM wave absorber by the basic site attenuation equation. We design the open-top hollow pyramidal new hybrid EM wave absorber consisted of 180cm long dielectric loss foam and ferrite tiles. Then, we design the 10m semi anechoic chamber by using the ray-tracing simulation and construct it in the size of L24m×W15.2m×H11.2m. More over, we measure the site attenuation of the constructed 10m semi anechoic chamber by using the broadband calculable dipole antennas. As the result, we confirm the validity of the designed open-top hollow pyramidal new hybrid EM wave absorber.

Kurihara, Hiroshi; Saito, Toshifumi; Suzuki, Yoshikazu; Nishikata, Atsuhiro; Hashimoto, Osamu

15

Effectiveness of an inlet flow turbulence control device to simulate flight fan noise in an anechoic chamber  

NASA Technical Reports Server (NTRS)

A hemispherical inlet flow control device was tested on a 50.8 cm. (20-inch) diameter fan stage in the NASA-Lewis Anechoic Chamber. The control device used honeycomb and wire mesh to reduce turbulence intensities entering the fan. Far field acoustic power level results showed about a 5 dB reduction in blade passing tone and about 10 dB reduction in multiple pure tone sound power at 90% design fan speed with the inlet device in place. Hot film cross probes were inserted in the inlet to obtain data for two components of the turbulence at 65 and 90% design fan speed. Without the flow control device the axial intensities were below 1.0%, while the circumferential intensities were almost twice this value. The inflow control device significantly reduced the circumferential turbulence intensities and also reduced the axial length scale.

Woodward, R. P.; Wazyniak, J. A.; Shaw, L. M.; Mackinnon, M. J.

1977-01-01

16

Realization of 3 m Semi Anechoic Chamber by Using Crossed-Wedge Shaped Hybrid EM Wave Absorber Consisting of Thin Corrugated Dielectric Lossy Sheet  

NASA Astrophysics Data System (ADS)

This letter proposes a new hybrid EM wave absorber with the crossed-wedge shape, which can be applied to 3m semi anechoic chambers. In this study, we designed a new hybrid EM wave absorber with the crossed-wedge shape, which consisted of the inorganic and organic thin corrugated dielectric lossy sheet containing organic conductive fibers. Then the 3m semi anechoic chamber is constructed in the size of 9.0m × 6.0m × 5.7m (L × W × H) using these absorbers, and also the normalized site attenuation (NSA) is measured according to ANSI C63.4 in the frequency range of 30MHz to 1GHz. As a result, the measured NSA is obtained within ±3dB of the theoretical one.

Saito, Toshifumi; Suzuki, Yoshikazu; Kurihara, Hiroshi

17

X-43A Undergoing Controlled Radio Frequency Testing in the Benefield Anechoic Facility at Edwards Ai  

NASA Technical Reports Server (NTRS)

The X-43A Hypersonic Experimental (Hyper-X) Vehicle hangs suspended in the cavernous Benefield Aenechoic Facility at Edwards Air Force Base during radio frequency tests in January 2000. Hyper-X, the flight vehicle for which is designated as X-43A, is an experimental flight-research program seeking to demonstrate airframe-integrated, 'air-breathing' engine technologies that promise to increase payload capacity for future vehicles, including hypersonic aircraft (faster than Mach 5) and reusable space launchers. This multiyear program is currently underway at NASA Dryden Flight Research Center, Edwards, California. The Hyper-X schedule calls for its first flight later this year (2000). Hyper-X is a joint program, with Dryden sharing responsibility with NASA's Langley Research Center, Hampton, Virginia. Dryden's primary role is to fly three unpiloted X-43A research vehicles to validate engine technologies and hypersonic design tools as well as the hypersonic test facility at Langley. Langley manages the program and leads the technology development effort. The Hyper-X Program seeks to significantly expand the speed boundaries of air-breathing propulsion by being the first aircraft to demonstrate an airframe-integrated, scramjet-powered free flight. Scramjets (supersonic-combustion ramjets) are ramjet engines in which the airflow through the whole engine remains supersonic. Scramjet technology is challenging because only limited testing can be performed in ground facilities. Long duration, full-scale testing requires flight research. Scramjet engines are air-breathing, capturing their oxygen from the atmosphere. Current spacecraft, such as the Space Shuttle, are rocket powered, so they must carry both fuel and oxygen for propulsion. Scramjet technology-based vehicles need to carry only fuel. By eliminating the need to carry oxygen, future hypersonic vehicles will be able to carry heavier payloads. Another unique aspect of the X-43A vehicle is the airframe integration. The body of the vehicle itself forms critical elements of the engine. The forebody acts as part of the intake for airflow and the aft section serves as the nozzle. The X-43A vehicles were manufactured by Micro Craft, Inc., Tullahoma, Tennessee. Orbital Sciences Corporation, Chandler, Arizona, built the Pegasus rocket booster used to launch the X-43 vehicles. For the Dryden research flights, the Pegasus rocket booster and attached X-43 will be air launched by Dryden's B-52 'Mothership.' After release from the B-52, the booster will accelerate the X-43A vehicle to the established test conditions (Mach 7 to 10) at an altitude of approximately 100,000 feet where the X-43 will separate from the booster and fly under its own power and preprogrammed control.

2000-01-01

18

Space Power Facility Reverberation Chamber Calibration Report  

NASA Technical Reports Server (NTRS)

This document describes the process and results of calibrating the Space Environmental Test EMI Test facility at NASA Plum Brook Space Power Facility according to the specifications of IEC61000-4-21 for susceptibility testing from 100 MHz to 40 GHz. The chamber passed the field uniformity test, in both the empty and loaded conditions, making it the world's largest Reverberation Chamber.

Lewis, Catherine C.; Dolesh, Robert J.; Garrett, Michael J.

2014-01-01

19

Electromagnetic Radiation (EMR) coupling to complex systems : aperture coupling into canonical cavities in reverberant and anechoic environments and model validation.  

SciTech Connect

Mode-stirred chamber and anechoic chamber measurements were made on two sets of canonical test objects (cylindrical and rectangular) with varying numbers of thin slot apertures. The shielding effectiveness was compared to determine the level of correction needed to compensate the mode-stirred data to levels commensurate with anechoic data from the same test object.

Charley, Dawna R.; Higgins, Matthew B.

2007-12-01

20

Target area chamber system design for the National Ignition Facility  

SciTech Connect

The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low activation material. The fusion reaction in the target gives off neutrons, x-ray and gamma rays. The x-rays and gamma rays interact with the interior of the target chamber wall while neutrons penetrate the wall. In order to minimize the neutron activation of components outside the target chamber and to absorb gammas emitted from the activated chamber, shielding will be placed immediately outside the chamber. The target chamber contains the target positioner. The target positioner moves the target from outside the chamber to the center of the chamber and positions the target at the focal spot of the laser beams. The target positioner must be survivable in a harsh radioactive environment. The materials used must be low activation and have a high stiffness to weight ratio to maintain target stability. This paper describes the conceptual design of the target chamber, target postioner, and shielding for the NIF.

Wavrik, R.; Boyes, J.; Olson, C.; Dempsey, F.; Garcia, R. [Sandia National Labs., Albuquerque, NM (United States); Karpenko, V.; Anderson, A.; Tobin, M.; Latkowski, J. [Lawrence Livermore National Lab., CA (United States)

1994-06-01

21

Anechoic Chamber o Echoless Room, existing equipment  

E-print Network

with a bar that doesn't allow the blocks to fall off will simulate gravity Alternative Energy o Solar #12;o Wind o Road that creates power as you drive over it Voice Modulator Sumo Bots Hybrid Cars #12;

Saskatchewan, University of

22

Static and wind tunnel near-field/far-field jet noise measurements from model scale single-flow base line and suppressor nozzles. Summary report. [conducted in the Boeing large anechoic test chamber and the NASA-Ames 40by 80-foot wind tunnel  

NASA Technical Reports Server (NTRS)

A test program was conducted in the Boeing large anechoic test chamber and the NASA-Ames 40- by 80-foot wind tunnel to study the near- and far-field jet noise characteristics of six baseline and suppressor nozzles. Static and wind-on noise source locations were determined. A technique for extrapolating near field jet noise measurements into the far field was established. It was determined if flight effects measured in the near field are the same as those in the far field. The flight effects on the jet noise levels of the baseline and suppressor nozzles were determined. Test models included a 15.24-cm round convergent nozzle, an annular nozzle with and without ejector, a 20-lobe nozzle with and without ejector, and a 57-tube nozzle with lined ejector. The static free-field test in the anechoic chamber covered nozzle pressure ratios from 1.44 to 2.25 and jet velocities from 412 to 594 m/s at a total temperature of 844 K. The wind tunnel flight effects test repeated these nozzle test conditions with ambient velocities of 0 to 92 m/s.

Jaeck, C. L.

1977-01-01

23

The Kevlar-walled anechoic wind tunnel  

NASA Astrophysics Data System (ADS)

The aerodynamic and acoustic performance of an anechoic wind tunnel test section with walls made from thin Kevlar cloth have been measured and analyzed. The Kevlar test section offers some advantages over a conventional free-jet arrangement. The cloth contains the bulk of the flow but permits the transmission of sound with little loss. The containment results in smaller far-field aerodynamic corrections meaning that larger models can be tested at higher Reynolds numbers. The containment also eliminates the need for a jet catcher and allows for a much longer test section. Model-generated noise is thus more easily separated from facility background using beamforming. Measurements and analysis of acoustic and aerodynamic corrections for a Kevlar-walled test section are presented and discussed, along with benchmark trailing edge noise measurements.

Devenport, William J.; Burdisso, Ricardo A.; Borgoltz, Aurelien; Ravetta, Patricio A.; Barone, Matthew F.; Brown, Kenneth A.; Morton, Michael A.

2013-08-01

24

Mode-Stirred Method Implementation for HIRF Susceptibility Testing and Results Comparison with Anechoic Method  

NASA Technical Reports Server (NTRS)

This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that test method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identified and implemented.

Nguyen, Truong X.; Ely, Jay J.; Koppen, Sandra V.

2001-01-01

25

Trade study comparing specimen chamber servicing methods for the Space Station Centrifuge Facility  

NASA Technical Reports Server (NTRS)

The Specimen Chamber Service Unit, a component of the Space Station Centrifuge Facility, must provide a clean enclosure on a continuing basis for the facility's plant, rodent and primate specimens. The specimen chambers can become soiled and can require periodic servicing to maintain a clean environment for the specimens. Two methods of servicing the specimen chambers are discussed: washing the chambers with an on-board washer, or disposing of the soiled chambers and replacing them with clean ones. Many of these issues are addressed by developing several servicing options, using either cleaning or replacement as the method of providing clean specimen chambers, and then evaluating each option according to a set of established quantitative and qualitative criteria. Disposing and replacing the Specimen Chambers is preferable to washing them.

Calvisi, Michael L.; Sun, Sidney C.

1991-01-01

26

Vocal effort levels in anechoic conditions  

Microsoft Academic Search

This paper presents statistical data on vocal effort levels in anechoic conditions from 50 British English speakers. Extending and rectifying the broadly quoted work carried out by Pearsons et al. in 1977 with American English speakers, the current work stipulates five vocal effort labels: hushed, normal, raised, loud and shout using a set of more precise descriptors with an aim

Ian R. Cushing; Francis F. Li; Trevor J. Cox; Ken Worrall; Tim Jackson

2011-01-01

27

Evaluation of Gas-filled Ionization Chamber Method for Radon Measurement at Two Reference Facilities  

SciTech Connect

For quality assurance, gas-filled ionization chamber method was tested at two reference facilities for radon calibration: EML (USA) and PTB (Germany). Consequently, the radon concentrations estimated by the ionization chamber method were in good agreement with the reference radon concentrations provided by EML as well as PTB.

Ishikawa, Tetsuo; Tokonami, Shinji; Kobayashi, Yosuke; Sorimachi, Atsuyuki; Yatabe, Yoshinori; Miyahara, Nobuyuki [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan)

2008-08-07

28

ABSORBER FOAM CHARACTERIZATION FOR PREDICTING OVERALL ANECHOIC CHAMBER PERFORMANCE  

E-print Network

polarizations for the source and receive horn antennas. For the frequency ranges 2.6GHz to 3.95GHz and 3.95GHz reflected signal, the direct path between the horn antennas is eliminated by placing a metal backed two Antenna Systems 130 Constitution Dr., Menlo Park, CA 94025 Dean Arakaki California Polytechnic State

Arakaki, Dean Y.

29

ATMOSPHERIC CHEMISTRY OF POTENTIAL EMISSIONS FROM FUEL CONVERSION FACILITIES. A SMOG CHAMBER STUDY  

EPA Science Inventory

The atmospheric chemistry of chemical species that may be emitted from fuel conversion facilities were studied in smog chambers. Of 17 compounds assessed for ozone-forming potential, 6 compounds were selected along with a control species, propylene, for testing in the presence of...

30

Performance of a drift chamber system for the time projection chamber detector facility at PEP - The PEP-4 TPC collaboration  

SciTech Connect

A system of two cylindrical drift chambers has been designed and constructed to trigger the Time Projection Chamber and to assist in tracking and momentum reconstruction. Performance of these chambers has been studied with data collected from cosmic rays and actual e/sup +/e/sup -/ collisions during recent experimental runs.

Aihara, H.; Alston-Garnjost, M.; Badtke, D.H.; Bakken, J.A.; Barbaro-Galtieri, A.; Barnes, A.V.; Barnett, B.A.; Blumenfeld, B.

1983-02-01

31

Target explosion generated fireballs in the nitrogen filled target chamber of the light ion fusion target development facility  

SciTech Connect

Molecular nitrogen is a possible choice for the target chamber gas in the light ion beam driven target development facility. The response of a nitrogen target chamber gas to fusion target explosions is considered. Targets with yields of 200 MJ, 400 MJ and 800 MJ are considered for a target chamber 3 m in radius and 6 m high which is filled with nitrogen gas at a density of 7.07 X 10/sup 17/ molecules/cm/sup 3/. The soft x-rays and ions from the explosion of these targets are stopped in short distances in this gas and create a hot spherical fireball in the center of the target chamber. Heat fluxes and shock pressures on the target chamber first walls due to these fireballs are presented and nitrogen is shown to be an acceptable cavity gas from the point of view of first wall loading.

Peterson, R.R.; Moses, G.A.

1983-09-01

32

Convolution of anechoic music with binaural impulse responses  

Microsoft Academic Search

The following paper presents the first results obtained in a recently growing-up Digital Signal Processing branch: the reconstruction of temporal and spatial characteristics of the sound field in a concert hall, starting from monophonic anechoic (dry) digital music recordings, and applying FIR filtering to obtain binaural (stereo) tracks. The FIR filters employed in this work are experimentally derived binaural impulse

Angelo Farina

33

Tests on an 8\\/100 scale model for the definition of the convergent and collector of CEPRA 19 \\/Anechoic open jet wind tunnel  

Microsoft Academic Search

An 8\\/100 scale model of the CEPRA 19 wind tunnel has been built in order to study and define the shape, size, and position of the jet collector in the tunnel's anechoic chamber. The jet collector is common to the 2 m and 3 m test sections, corresponding to free jet lengths of 5.42 D and 3.96 D, respectively. The

P. Rebuffet; A. Guedel

1981-01-01

34

Design and performance of the vacuum chambers for the undulator of the VUV FEL at the TESLA test facility at DESY  

NASA Astrophysics Data System (ADS)

Three vacuum chambers for the VUV SASE FEL undulator sections at the TESLA Test Facility (TTF) were designed, built, tested and installed. Each chamber is 4.5 m long and of 11.5 mm thick. The inner diameter of the beam pipe is 9.5 mm. The rectangular chamber profile with a width of 128 mm is used to integrate beam position monitors and steerers. This is needed to provide a good overlap between the electron and the photon beam over the entire undulator length. The chambers are built in an aluminum extrusion technology developed for the insertion device vacuum chambers of the Advanced Photon Source. After manufacturing, special processing was performed to reach low outgassing rates (<1×10 -11mbar·l/s·cm 2) and particle-free chambers. Mounting of the chambers at TTF were performed under clean room conditions better class 100.

Hahn, U.; den Hartog, P. K.; Pflüger, J.; Rüter, M.; Schmidt, G.; Trakhtenberg, E. M.

2000-05-01

35

Inlet turbulence and fan noise measured in an anechoic wind tunnel and statically with an inlet flow control device  

NASA Technical Reports Server (NTRS)

Turbulence and acoustic measurements were taken in the NASA-Lewis anechoic wind tunnel - a facility which has demonstrated the blade passage tone cutoff phenomena with forward velocity. Turbulence data were taken in a subsonic inlet at various fan speeds under static and forward velocity conditions. A honeycomb/screen flow control device was placed over the inlet during static tests to modify the inflow in an attempt to simulate flight conditions. Acoustic levels of the blade passage tone along with transverse turbulence intensities were reduced with forward velocity. The flow control device reduced the blade passage tone to an intermediate level between those levels associated with static and forward velocity operation.

Shaw, L. M.; Woodward, R. P.; Glaser, F. W.; Dastoli, B. J.

1977-01-01

36

Classification of heart valve sounds from experiments in an anechoic water tank  

SciTech Connect

In vivo studies in both sheep and humans were plagued by a number of problems including movement artifacts, biological noise, low signal-to-noise ratio (SNR), chest-wall reverberation, and limited bandwidth recordings as discussed by [1]. To overcome these problems it was decided to record heart valve sounds under controlled conditions deep in an anechoic water tank, free from reverberation noise, including surface reflections. Experiments were conducted in a deep water tank at the Transdec facility in San Diego, which satisfies these requirements. The Transdec measurements are free of reverberations, but not totally free of acoustic and electrical noise. We used a high quality hydrophone together with a wide-band data acquisition system [2]. We recorded sounds from 100 repetitions of the opening-closing cycles on each of 50 different heart valves, including 21 SLS valves and 29 intact valves. The power spectrum of the opening and closing phases of each cycle were calculated and outlier spectra removed as described by Candy [2]. In this report, we discuss the results of our classification of the heart valve sound measurements. The goal of this classification task was to apply the fundamental classification algorithms developed for the clinical data in 1994 and 1996 to the measurements from the anechoic water tank. From the beginning of this project, LLNL's responsibility has been to process and classify the heart valve opening sounds. For this experiment, however, we processed both the opening sounds and closing sounds for comparison purposes. The results of this experiment show that the classifier did not perform well. We believe this is because of low signal-to-noise ratio and excessive variability in signal power from beat-to-beat for a given valve.

Axelrod, M C; Clark, G A; Scott, D

1999-06-01

37

Classification of heart valve sounds from experiments in an anechoic water tank  

SciTech Connect

In vivo studies in both sheep and humans were plagued by a number of problems including movement artifacts, biological noise, low signal-to-noise ratio (SNR), chest-wall reverberation, and limited bandwidth recordings as discussed by [1]. To overcome these problems it was decided to record heart valve sounds under controlled conditions deep in an anechoic water tank, free from reverberation noise. The main goal of this experiment was to obtain measurements of ''pure'' heart valve sounds free of the scattering effects of the body. Experiments were conducted at the Transdec facility in San Diego [2]. We used a high quality hydrophone together with a wide-band data acquisition system [2]. We recorded sounds from 100 repetitions of the opening-closing cycles on each of 50 different heart valves, including 21 SLS valves and 29 intact valves. The power spectrum of the opening and closing phases of each cycle were calculated and outlier spectra removed as described by Candy [2]. In this report, we discuss the results of our classification of the heart valve sound measurements. The goal of this classification task was to apply the fundamental classification algorithms developed for the clinical data in 1994 and 1996 to the measurements from the anechoic water tank. From the beginning of this project, LLNL's responsibility has been to process and classify the heart valve sounds. For this experiment, however, we processed both the opening sounds and closing sounds for comparison purposes. The results of this experiment show that the classifier did not perform well because of low signal-to-noise ratio and excessive variability in signal power from beat-to-beat for a given valve.

Axelrod, M C; Clark, G A; Scott, D

1999-06-01

38

A Concept for a Low Pressure Noble Gas Fill Intervention in the IFE Fusion Test Facility (FTF) Target Chamber  

SciTech Connect

An engineering evaluation has been initiated to investigate conceptual engineering methods for implementing a viable gas shield strategy in the Fusion Test Facility (FTF) target chamber. The employment of a low pressure noble gas in the target chamber to thermalize energetic helium ions prior to interaction with the wall could dramatically increase the useful life of the first wall in the FTF reactor1. For the purpose of providing flexibility, two target chamber configurations are addressed: a five meter radius sphere and a ten meter radius sphere. Experimental studies at Nike have indicated that a low pressure, ambient gas resident in the target chamber during laser pulsing does not appear to impair the ability of laser light from illuminating targets2. In addition, current investigations into delivering, maintaining, and processing low pressure gas appear to be viable with slight modification to current pumping and plasma exhaust processing technologies3,4. Employment of a gas fill solution for protecting the dry wall target chamber in the FTF may reduce, or possibly eliminate the need for other attenuating technologies designed for keeping He ions from implanting in first wall structures and components. The gas fill concept appears to provide an effective means of extending the life of the first wall while employing mostly commercial off the shelf (COTS) technologies. Although a gas fill configuration may provide a methodology for attenuating damage inflicted on chamber surfaces, issues associated with target injection need to be further analyzed to ensure that the gas fill concept is viable in the integrated FTF design5. In the proposed system, the ambient noble gas is heated via the energetic helium ions produced by target detonation. The gas is subsequently cooled by the chamber wall to approximately 800oC, removed from the chamber, and processed by the chamber gas processing system (CGPS). In an optimized scenario of the above stated concept, the chamber wall acts as the primary heat exchanger. During removal, gas is pumped through the laser ports by turbo molecular-drag pumps (TM-DP). For the purpose of reducing organic based lubricants and seals, a magnetically levitated TM-DP is being investigated with pump manufacturers. Currently, magnetically levitated turbo molecular pumps are commercially available. The pumps will be exposed to thermal loads and ionizing radiation (tritium, Ar-41, post detonation neutrons). Although the TM-DP's will be subjected to these various radiations, current designs for similar pumping devices have been hardened and have the ability of locating control electronics in remote radiation shielded enclosures4. The radiation hardened TM-DP's will be 5 required to operate with minimal maintenance for periods of up to 18 continuous months. As part of this initial investigation for developing a conceptual engineering strategy for a gas fill solution, commercial suppliers of low pressure gas pumping systems have been contacted and engaged in this evaluation. Current technology in the area of mechanical pumping systems indicates that the development of a robust pumping system to meet the requirements of the FTF gas fill concept is within the limits of COTS equipment3,4.

C.A. Gentile, W.R. Blanchard, T.A. Kozub, M. Aristova, C. McGahan, S. Natta, K. Pagdon, J. Zelenty

2010-01-14

39

Management of unconverted light for the National Ignition Facility target chamber  

SciTech Connect

The NIF target chamber beam dumps must survive high x-ray, laser, ion, and shrapnel exposures without excessive generation of vapors or particulate that will contaminate the final optics debris shields, thereby making the debris shields susceptible to subsequent laser damage. The beam dumps also must be compatible with attaining and maintaining the required target chamber vacuum and must not activate significantly under high neutron fluxes. Finally, they must be developed, fabricated, and maintained for a reasonable cost. The primary challenge for the beam dump is to survive up to 20 J/cm{sup 2} of lpm light and 1 - 2 J/cm{sup 2} of nominally 200 - 350 eV blackbody temperature x rays. Additional threats include target shrapnel, and other contamination issues. Designs which have been evaluated include louvered hot-pressed boron carbide (B{sub 4}C) or stainless steel (SS) panels, in some cases covered with transparent Teflon film, and various combinations of inexpensive low thermal expansion glasses backed by inexpensive absorbing glass. Louvered designs can recondense a significant amount of ablated material that would otherwise escape into the target chamber. Transparent Teflon was evaluated as an alternative way to capture ablated material. The thin Teflon sheet would need to be replaced after each shot since it exhibits both laser damage and considerable x- ray ablation with each shot. Uncontaminated B{sub 4}C, SS, and low thermal expansion glasses have reasonably small x-ray and laser ablation rates, although the glasses begin to fail catastrophically after 100 high fluence shots. Commercially available absorbing glasses require a pre-shield of either Teflon or low thermal expansion glass to prevent serious degradation by the x-ray fluence. Advantages of the hot-pressed B{sub 4}C and SS over glass are their performance against microshrapnel, their relative indifference to contamination, and their ability to be refurbished by aggressive cleaning using CO{sub 2} pellets, glass beads, high pressure water or ultrasonic tanks. In addition the expected replacement rate to avoid catastrophic failure makes the glass option more costly. SS is less expensive, more easily formed into a louver design with high capture efficiency, and otherwise equivalent to B{sub 4}C. Hence, it would be preferred as long as debris shield damage is not substantially greater for SS as compared to damage from an equivalent mass of contamination of B{sub 4}C. If debris shield damage is problematic, the escape of SS could be mitigated by use of a transparent Teflon film. The Teflon film would require increased target chamber pumping and cleaning capability to accommodate the x-ray decomposition products.

Anderson, A. T.; Bletzer, K.; Burnham, A. K.; Dixit, S; Genin, F. Y.; Hibbard, W.; Norton, J.; Scott, J. M.; Whitman, P. K.

1998-07-08

40

Mars and Lunar Vacuum Chamber Testing Facilities and Vacuum Rated Drill Systems  

NASA Astrophysics Data System (ADS)

Martian and Lunar low pressure and vacuum conditions, respectively, greatly affect the performance of the drilling mechanics and drill hardware. For this reason, it is imperative to test planetary sampling and coring drills under these specific environments. Honeybee Robotics acquired an 11ft vacuum chamber that is currently being used to test drills to 1m depth and more. A separate cooling system is used to maintain low temperature of planetary analog formations such as ice, soil, icy-soils, and rocks. The low temperature increases the strength of these formations and in turn reduces drilling efficiency. The chamber also has a numerous feed troughs that can be used to transfer thermal data from thermocouples embedded inside the drilled sample, and the drill bits. The thermal data is useful to determine the temperature the sample reaches during the drilling process. The drill systems include rotary, rotary-percussive, and rotary-sonic. The latter two, in particular, offer superior performance in hard formations due to impacts and/or vibrations that enhance penetration rate. All the drill systems are vacuum rated and hence can be used as test platforms for vacuum testing.

Zacny, K.; Paulsen, G.; Craft, J.; Maksymuk, M.; Santoro, C.; Wilson, J.

2009-12-01

41

Decompression sickness rates for chamber personnel: case series from one facility.  

PubMed

During 2004, a case series of decompression sickness (DCS) meeting the definition of epidemic DCS was observed in the Shaw AFB Physiological Training Program. There were 10 cases of chamber-induced altitude DCS observed. Internal and external investigations focused on time, place, person, and environment. No temporal trend was observed. Chamber, masks, regulators, crew positions, and oxygen sources revealed no defects. Among the cases, mean age was 27 yr. Peak altitude in four cases was 35,000 ft and in the other six cases was 25,000 ft. Six had joint pain, one skin symptoms, and three neurological findings. Four were treated with 100% ground-level oxygen and six with hyperbaric oxygen. Four were students and six were inside observers (IO). Four were women and six men. In the IO, where four of the six were women, no gender effect was seen. Examining the IO monthly exposure load (exposures per month) against DCS suggested a dose-response relationship. This relationship held true when 4 yr of Shaw AFB IO data was studied. Indeed, Poisson regression analysis demonstrated a statistically significant 2.1-fold rise in DCS risk with each monthly exposure. Consequently, the number of exposures per month may need to be considered when devising IO schedules. PMID:19522370

Brandt, Megan S; Morrison, Thomas O; Butler, William P

2009-06-01

42

Ultra-light duct for an anechoic wind tunnel  

NASA Technical Reports Server (NTRS)

A tunnel ultra-light (or TUL) is a duct composed of acoustically transparent cloth designed to transform an open-jet wind tunnel into a closed-jet wind tunnel. This concept is of interest (a priori) for anechoic wind tunnels because it improves the aerodynamic quality without hindering the measurement of sound in the far field. A full scale device designed for the 3 m diameter test section of CEPRA 19 was described. The apparatus installation did not develop any significant problems, and the mechanical support turned out to be excellent. Aerodynamic and acoustic tests are discussed. Certain imperfections in the installation as tested - instabilities above 25 m/s and acceptable cloth transmission up to 4kHz were revealed. The system as tested could eventually be used in certain applications, for example, in ground based transport. However, the concept of TUL must be developed further to arrive at a reliable mechanism for use in a large number of applications.

Lambourion, J.; Lewy, S.; Papirnyk, O.; Rahier, G.; Remandet, J.-N.

1989-01-01

43

Comparison of particle velocity and sound pressure measurements in anechoic and medfly bioassay chambers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many insects without tympanal ears do not perceive the pressure component of sound, but instead have movement receptors (usually small hairs on body or antennae) that are sensitive to sound particle velocity -- oscillations of air particles in the sound field. In our laboratory, efforts to develop...

44

Archiving Quality Control Tests in the PHENIX Resistive Plate Chamber Assembly Facility  

NASA Astrophysics Data System (ADS)

The PHENIX collaboration at RHIC studies polarized proton-proton collisions to better understand the spin structure of the proton. PHENIX is in the process of upgrading the muon trigger to improve our capabilities of selecting the muons from the decay of W-bosons which are produced more readily at a high transverse momentum than other muon sources. By triggering on single, high transverse momentum muons, new observations on the spin asymmetries of a proton can be obtained. The trigger upgrade will consist of four stations of Resistive Plate Chambers (RPCs), with stations on each side of the interaction region. Each RPC consists of two Bakelite gas gaps, a copper signal plane, an aluminum case, and several layers of mylar and copper. With all of these parts comes the need to archive the manufacturing and quality assurance information along with test results performed on them. This information is kept in a Postgresql Database in the RPC factory and is maintained, modified, and read out through several PHP web pages. A new output page has been produced that will make all of this information much more accessible. This poster will focus on what data is archived, how it is stored, and how it can be easily retrieved and put to use.

Andrews, Keller

2009-10-01

45

Simulation of Flight-Type Engine Fan Noise in the NASA-Lewis 9X15 Anechoic Wind Tunnel  

NASA Technical Reports Server (NTRS)

Flight type noise as contrasted to the usual ground static test noise exhibits substantial reductions in the time unsteadiness of tone noise, and in the mean level of tones calculated to be nonpropagating or cut-off. A model fan designed with cuttoff of the fundamental tone was acoustically tested in the anechoic wind tunnel under both static and tunnel flow conditions. The properties that characterize flight type noise were progressively simulated with increasing tunnel flow. The distinctly lobed directivity pattern of propagating rotor/stator interaction modes was also observed. Excess noise attributed to the ingestion of the flow disturbances that prevail near most static test facilities is substantially reduced with tunnel flow.

Heidmann, M. F.; Dietrich, D. A.

1976-01-01

46

CFD Simulation on the J-2X Engine Exhaust in the Center-Body Diffuser and Spray Chamber at the B-2 Facility  

NASA Technical Reports Server (NTRS)

A computational fluid dynamic (CFD) code is used to simulate the J-2X engine exhaust in the center-body diffuser and spray chamber at the Spacecraft Propulsion Facility (B-2). The CFD code is named as the space-time conservation element and solution element (CESE) Euler solver and is very robust at shock capturing. The CESE results are compared with independent analysis results obtained by using the National Combustion Code (NCC) and show excellent agreement.

Wang, Xiao-Yen; Wey, Thomas; Buehrle, Robert

2009-01-01

47

Flow chamber  

DOEpatents

A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

Morozov, Victor (Manassas, VA)

2011-01-18

48

Binaural Simulation Experiments in the NASA Langley Structural Acoustics Loads and Transmission Facility  

NASA Technical Reports Server (NTRS)

A location and positioning system was developed and implemented in the anechoic chamber of the Structural Acoustics Loads and Transmission (SALT) facility to accurately determine the coordinates of points in three-dimensional space. Transfer functions were measured between a shaker source at two different panel locations and the vibrational response distributed over the panel surface using a scanning laser vibrometer. The binaural simulation test matrix included test runs for several locations of the measuring microphones, various attitudes of the mannequin, two locations of the shaker excitation and three different shaker inputs including pulse, broadband random, and pseudo-random. Transfer functions, auto spectra, and coherence functions were acquired for the pseudo-random excitation. Time histories were acquired for the pulse and broadband random input to the shaker. The tests were repeated with a reflective surface installed. Binary data files were converted to universal format and archived on compact disk.

Grosveld, Ferdinand W.; Silcox, Richard (Technical Monitor)

2001-01-01

49

Performance of the high speed anechoic wind tunnel at Lyon University  

NASA Technical Reports Server (NTRS)

The characteristics of the feed duct, the wind tunnel, and the experiments run in the convergent-divergent anechoic wind tunnel at Lyon University are described. The wind tunnel was designed to eliminate noise from the entrance of air or from flow interactions with the tunnel walls so that noise caused by the flow-test structure interactions can be studied. The channel contains 1 x 1 x 0.2 m glass and metal foil baffles spaced 0.2 m apart. The flow is forced by a 350 kW fan in the primary circuit, and a 110 kW blower in the secondary circuit. The primary circuit features a factor of four throat reductions, followed by a 1.6 reduction before the test section. Upstream and downstream sensors permit monitoring of the anechoic effectiveness of the channel. Other sensors allow modeling of the flow structures in the tunnel. The tunnel was used to examine turbulent boundary layers in flows up to 140 m/sec, tubulence-excited vibrations in walls, and the effects of laminar and turbulent flows on the appearance and locations of noise sources.

Sunyach, M.; Brunel, B.; Comte-Bellot, G.

1986-01-01

50

Exposure chamber  

DOEpatents

A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

Moss, Owen R. (Kennewick, WA)

1980-01-01

51

Wire chamber  

DOEpatents

A wire chamber or proportional counter device, such as Geiger-Mueller tube or drift chamber, improved with a gas mixture providing a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor.

Atac, Muzaffer (Wheaton, IL)

1989-01-01

52

Anechoic coatings obtained from two- and three-dimensional monopole resonance diffraction gratings.  

PubMed

Underwater sound reflections can be reduced in magnitude by a rubber coating including three-dimensional (3-D) cavities forming a doubly periodic diffraction grating. A monopole resonance for sphere-like cavities enhances absorption in the surrounding rubber solid. A corresponding resonance for an infinite cylinder is studied in the present paper. Appearing at a considerably lower frequency than for a sphere with the same radius, it suggests the possibility of much thinner anechoic coatings including cylindrical cavities, with axes in a lateral direction, forming a diffraction grating with a single period. This is effectively a 2-D case, because of invariance in the axial direction. Subsequent coating design computations, using the layer-multiple-scattering method and including cavities of different sizes, show improved reflection reduction with coatings only about one third as thick. Still accounting for multiple scattering among the cavities and capturing the essential physics, the monopole approximation is applied to advance the analytic study of the reflection reduction. An energy decomposition relation is derived and used to quantify the absorption of the incident sound energy by cavities of different sizes. Coatings based on filled inclusions and other resonance effects are briefly considered. Again, the 2-D alternative with cylinders of mixed sizes gives thinner coatings. PMID:22501043

Ivansson, Sven M

2012-04-01

53

Ionization chamber  

DOEpatents

An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

Walenta, Albert H. (Port Jefferson Station, NY)

1981-01-01

54

meters in CO2 euthanasia chambers. All CO2 euthanasia chambers in both  

E-print Network

meters in CO2 euthanasia chambers. All CO2 euthanasia chambers in both the facilities and laboratories will need flow meters. ULAR is currently in the process of identifying a cost-effective, accurate, and durable flow meter to install in all of the CO2 chambers in all of the vivaria. When a specific model

Bushman, Frederic

55

Magma chambers  

NASA Technical Reports Server (NTRS)

Recent observational and theoretical investigations of terrestrial magma chambers (MCs) are reviewed. Consideration is given to the evidence for MCs with active convection and crystal sorting, problems of direct MC detection, theoretical models of MC cooling, the rheology and dynamics of solidification fronts, crystal capture and differentiation, convection with solidification, MC wall flows, and MC roof melting. Diagrams, graphs, and a list of problems requiring further research are provided.

Marsh, Bruce D.

1989-01-01

56

Alignment of an x-ray imager line of sight in the National Ignition Facility (NIF) target chamber using a Diagnostic Instrument Manipulator (DIM) and Opposed Port Alignment System (OPAS)  

NASA Astrophysics Data System (ADS)

The National Ignition Facility (NIF) fields multiple varieties of x-ray imaging systems used to diagnose the implosion physics of laser-driven fusion targets. The imagers consist of time-resolved x-ray detectors coupled with a snout assembly for spatial and/or spectral imaging. The instrument is mounted onto a cart that extends into the NIF target chamber, placing it in close proximity to the target and aligning with a tight tolerance using the Opposed Port Alignment System (OPAS). The OPAS is a modified, commercial Schmidt-Cassegrain optical telescope mounted at the target chamber port, opposite the Diagnostic Instrument Manipulator (DIM). In this paper, the approach used to characterize and align the x-ray imaging instruments is described. The characterization includes offline measurements of the pinhole assembly and the detector housing. Online, deviations of the DIM, as it is inserted along rails toward the target chamber center, are characterized and related to the OPAS view. An overview of the offline measurement stations is provided along with the process to develop the relationship between the offline alignment scopes and the OPAS as a function of DIM insertion. The combination of these measurements is used to mathematically construct the predicted location of the x-ray imager line of sight in the OPAS image space and determine the desired pinhole location to record data on a fusion experiment. The alignment accuracy of this approach will be discussed, as demonstrated with various x-ray instruments and pinhole configurations.

Shingleton, N.; Kalantar, D.; Wood, R.; McCarville, T.; Klingmann, J.; Manuel, A.

2012-10-01

57

Chamber B Thermal/Vacuum Chamber: User Test Planning Guide  

NASA Technical Reports Server (NTRS)

Test process, milestones and inputs are unknowns to first-time users of Chamber B. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

Montz, Mike E.

2012-01-01

58

D0 central tracking chamber performance studies  

SciTech Connect

The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an R{Phi} tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against {gamma} {yields} e {sup +} e{sup {minus}} events.

Pizzuto, D.

1991-12-01

59

Portable Hyperbaric Chamber  

NASA Technical Reports Server (NTRS)

A portable, collapsible hyperbaric chamber was developed. A toroidal inflatable skeleton provides initial structural support for the chamber, allowing the attendant and/or patient to enter the chamber. Oval hatches mate against bulkhead rings, and the hyperbaric chamber is pressurized. The hatches seal against an o-ring, and the internal pressure of the chamber provides the required pressure against the hatch to maintain an airtight seal. In the preferred embodiment, the hyperbaric chamber has an airlock to allow the attendant to enter and exit the patient chamber during treatment. Visual communication is provided through portholes in the patient and/or airlock chamber. Life monitoring and support systems are in communication with the interior of the hyperbaric chamber and/or airlock chamber through conduits and/or sealed feed-through connectors into the hyperbaric chamber.

Schneider, William C. (Inventor); Locke, James P. (Inventor); DeLaFuente, Horacio (Inventor)

2001-01-01

60

Two chamber reaction furnace  

DOEpatents

A vertical two chamber reaction furnace is described. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 C and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

Blaugher, R.D.

1998-05-05

61

Hyperphysics: The Cloud Chamber  

NSDL National Science Digital Library

This Hyperphysics webpage contains a short description of the Wilson cloud chamber and two photographs by Wilson himself of cloud chamber tracks. Links provides information about various methods of detecting radiation and also about the muon, an elementary particle that was first detected in a cloud chamber. The text on this page is written at a level of a student of introductory physics.

Nave, Carl R.

2008-11-26

62

Temperature Studies for ATLAS MDT BOS Chambers  

E-print Network

Data sets with high statistics taken at the cosmic ray facility, equipped with 3 ATLAS BOS MDT chambers, in Garching (Munich) have been used to study temperature and pressure effects on gas gain and drifttime. The deformation of a thermally expanded chamber was reconstructed using the internal RasNik alignment monitoring system and the tracks from cosmic data. For these studies a heating system was designed to increase the temperature of the middle chamber by up to 20 Kelvins over room temperature. For comparison the temperature effects on gas properties have been simulated with Garfield. The maximum drifttime decreased under temperature raise by -2.21 +- 0.08 ns/K, in agreement with the results of pressure variations and the Garfield simulation. The increased temperatures led to a linear increase of the gas gain of about 2.1% 1/K. The chamber deformation has been analyzed with the help of reconstructed tracks. By the comparison of the tracks through the reference chambers with these through the test chamber the thermal expansion has been reconstructed and the result shows agreement with the theoretical expansion coefficient. As the wires are fixed at the end of the chamber, the wire position calculation can not provide a conclusion for the chamber middle. The complete deformation has been identified with the analysis of the monitoring system RasNik, whose measured values have shown a homogeneous expansion of the whole chamber, overlayed by a shift and a rotation of the chamber middle with respect to the outer part of the chamber. The established results of both methods are in agreement. We present as well a model for the position-drifttime correction as function of temperature.

A. Engl; O. Biebel; R. Hertenberger; R. Mameghani; D. Merkl; F. Rauscher; D. Schaile; R. Stroehmer

2009-08-11

63

Stove with multiple chambers  

SciTech Connect

A stove is described for burning a solid fuel such as wood. The wall means defines a main air inlet, a combustion gas outlet, and four chambers through which gas passes sequentially from the main air inlet to the combustion gas outlet. The chambers comprises a pre-heat plenum chamber into which the main air inlet opens. A main combustion chamber contains solid fuel to be burned into which gas passes from the pre-heat plenum chamber, a second combustion chamber which is downstream of the main combustion chamber with respect to the flow of gas from the main air inlet to the combustion gas outlet, and a third combustion chamber from which the combustion gas outlet opens. The stove also comprises a plate having a restricted opening for providing communication between the second and third combustion chambers. And a catalytic converter comprises a body of solid material formed with passageways, the body of solid material being fitted in the restricted opening so that gas passes from the second combustion chamber to the third combustion chamber by way of the passageways in the body.

Black, A.

1987-04-21

64

BOREAS TGB-1 NSA SF6 Chamber Flux Data  

NASA Technical Reports Server (NTRS)

The BOREAS TGB-1 team made several chamber and tower measurements of trace gases at sites in the BOREAS NSA. This data set contains sulfur hexafluoride (SF6) dark chamber flux measurements at the NSA-OJP and NSA-YJP sites from 16-May through 13-Sep-1994. Gas samples were extracted approximately every 7 days from dark chambers and analyzed at the NSA lab facility. The data are provided in tabular ASCII files.

Crill, Patrick; Varner, Ruth K.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

65

16. NBS TOPSIDE CONTROL ROOM, THE NBS HYPERBARIC CHAMBER IS ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. NBS TOPSIDE CONTROL ROOM, THE NBS HYPERBARIC CHAMBER IS VERY CLOSE TO THE WATER'S EDGE AND HERE FOR DIVER EMERGENCY SUPPORT. A MEDICAL STAFF IS LOCATED ON THE MARSHALL SPACE FLIGHT CENTER (MSFC) AND SUPPORTS THE NBS PERSONNEL WHEN HYPERBARIC CHAMBER OPERATION IS NECESSARY. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

66

Evaluation of Carbon Dioxide Dissipation within a Euthanasia Chamber  

PubMed Central

CO2 euthanasia is used widely for small laboratory animals, such as rodents. A common necessity in many animal research facilities is to euthanize mice in sequential batches. We assessed the effects of several variables on the time it took for CO2 to dissipate within a chamber. Using standard euthanasia time, changes in flow rate were compared between a slow 15% fill rate for 7 min, and a slow 15% followed by a rapid 50% filling for a total of 5 min. Additional variables assessed included the effects of opening the lid after the completion of chamber filling, turning the chamber over after completion of filling, and the use and removal of a cage from within the chamber. For all trials, CO2 levels in the chambers peaked between 50% and 80%. After the gas was turned off, the concentration of CO2 dropped to below 10% CO2 within 2 min, except when the lid was left on the chamber, where concentration levels remained above 10% after 20 min. CO2 dissipation was significantly faster when the chamber was turned upside down after filling. Significant interaction effects occurred among the factors of cage presence within the chamber, flow rate, and chamber position. Only leaving the lid on the chamber had any practical implication for delaying CO2 dissipation. We recommend that users allow 2 min for CO2 to clear from the chamber before subsequent euthanasia procedures, unless the chamber is manipulated to increase the dissipation rate. PMID:25199098

Djoufack-Momo, Shelly M; Amparan, Ashlee A; Grunden, Beverly; Boivin, Gregory P

2014-01-01

67

High resolution drift chambers  

SciTech Connect

High precision drift chambers capable of achieving less than or equal to 50 ..mu..m resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs.

Va'vra, J.

1985-07-01

68

A comparison of the acoustic and aerodynamic measurements of a model rotor tested in two anechoic wind tunnels  

NASA Technical Reports Server (NTRS)

Two aeroacoustic facilities--the CEPRA 19 in France and the DNW in the Netherlands--are compared. The two facilities have unique acoustic characteristics that make them appropriate for acoustic testing of model-scale helicopter rotors. An identical pressure-instrumented model-scale rotor was tested in each facility and acoustic test results are compared with full-scale-rotor test results. Blade surface pressures measured in both tunnels were used to correlated nominal rotor operating conditions in each tunnel, and also used to assess the steadiness of the rotor in each tunnel's flow. In-the-flow rotor acoustic signatures at moderate forward speeds (35-50 m/sec) are presented for each facility and discussed in relation to the differences in tunnel geometries and aeroacoustic characteristics. Both reports are presented in appendices to this paper. ;.);

Boxwell, D. A.; Schmitz, F. H.; Splettstoesser, W. R.; Schultz, K. J.; Lewy, S.; Caplot, M.

1986-01-01

69

Rapid sampling culture chamber.  

PubMed Central

An all-glass chamber for culturing anaerobic and aerobic bacteria in liquid medium is described. The system permits both rapid sampling and turbidimetric measurements under controlled atmospheric conditions. PMID:350159

Carey, A E; Schroeder, B W

1978-01-01

70

The KLOE drift chamber  

Microsoft Academic Search

The tracking detector of the KLOE experiment is 4m diameter, 3.3m length drift chamber, designed to contain a large fraction of the decays of low-energy KL produced at the Frascati DA?NE ?-factory. The chamber is made by a thin carbon fiber structure and operated with a helium-based gas mixture in order to minimise conversion of low-energy photons and multiple scattering

M. Adinolfi; A. Aloisio; F. Ambrosino; A. Andryakov; A. Antonelli; M. Antonelli; F. Anulli; C. Bacci; A. Bankamp; G. Barbiellini; F. Bellini; G. Bencivenni; S. Bertolucci; C. Bini; C. Bloise; V. Bocci; F. Bossi; P. Branchini; S. A. Bulychjov; G. Cabibbo; A. Calcaterra; R. Caloi; P. Campana; G. Capon; G. Carboni; A. Cardini; M. Casarsa; G. Cataldi; F. Ceradini; F. Cervelli; F. Cevenini; G. Chiefari; P. Ciambrone; S. Conetti; S. Conticelli; E. De Lucia; G. De Robertis; R. De Sangro; P. De Simone; G. De Zorzi; S. Dell'Agnello; A. Denig; A. Di Domenico; C. Di Donato; S. Di Falco; A. Doria; E. Drago; V. Elia; O. Erriquez; A. Farilla; G. Felici; A. Ferrari; M. L. Ferrer; G. Finocchiaro; C. Forti; A. Franceschi; P. Franzini; M. L. Gao; C. Gatti; P. Gauzzi; S. Giovannella; V. Golovatyuk; E. Gorini; F. Grancagnolo; W. Grandegger; E. Graziani; P. Guarnaccia; U. v. Hagel; H. G. Han; S. W. Han; X. Huang; M. Incagli; L. Ingrosso; Y. Y. Jang; W. Kim; W. Kluge; V. Kulikov; F. Lacava; G. Lanfranchi; J. Lee-Franzini; F. Lomtadze; C. Luisi; C. S. Mao; M. Martemianov; M. Matsyuk; W. Mei; L. Merola; R. Messi; S. Miscetti; A. Moalem; S. Moccia; M. Moulson; S. Mueller; F. Murtas; M. Napolitano; A. Nedosekin; M. Panareo; L. Pacciani; P. Pagès; M. Palutan; L. Paoluzi; E. Pasqualucci; L. Passalacqua; M. Passaseo; A. Passeri; V. Patera; E. Petrolo; G. Petrucci; D. Picca; G. Pirozzi; C. Pistillo; M. Pollack; L. Pontecorvo; M. Primavera; F. Ruggieri; P. Santangelo; E. Santovetti; G. Saracino; R. D. Schamberger; C. Schwick; B. Sciascia; A. Sciubba; F. Scuri; I. Sfiligoi; J. Shan; P. Silano; T. Spadaro; S. Spagnolo; E. Spiriti; C. Stanescu; G. L. Tong; L. Tortora; E. Valente; P. Valente; B. Valeriani; G. Venanzoni; S. Veneziano; Y. Wu; Y. G. Xie; P. P. Zhao; Y. Zhou

2001-01-01

71

Mercury Chamber Considerations  

E-print Network

Mercury Chamber Considerations V. Graves IDS-NF Target Studies July 2011 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Mercury Chamber Considerations, July 2011 Flow Loop Review · 1 cm dia nozzle, 20 m/s jet requires 1.57 liter/sec mercury flow (94.2 liter/min, 24.9 gpm). · MERIT experiment

McDonald, Kirk

72

OUTDOOR CHAMBER STUDY TO TEST MULTI-DAY EFFECTS. VOLUME 1. RESULTS AND DISCUSSION  

EPA Science Inventory

The smog chamber facilities of the University of California, Riverside were used to collect experimental data to assess the effects of multi-day irradiations on photochemical oxidant formation. Two chambers were used during this program: a 6,400-l indoor Teflon chamber with black...

73

Sleeve reaction chamber system  

DOEpatents

A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

Northrup, M. Allen (Berkeley, CA); Beeman, Barton V. (San Mateo, CA); Benett, William J. (Livermore, CA); Hadley, Dean R. (Manteca, CA); Landre, Phoebe (Livermore, CA); Lehew, Stacy L. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA)

2009-08-25

74

A comparison of the microwave oven and reverberation chamber  

Microsoft Academic Search

The reverberation chamber is a facility mainly for electromagnetic compatibility (EMC) tests whilst the microwave oven is used for heating applications. They both generate a time-averaged uniform field in the area of interest. In this paper, these two facilities are compared in terms of their applications, operation principles, design philosophy and especially the field uniformity with the aid of electromagnetic

Yi Huang; Xu Zhu; Binoy Nair

2005-01-01

75

Terminal configured vehicle program: Test facilities guide  

NASA Technical Reports Server (NTRS)

The terminal configured vehicle (TCV) program was established to conduct research and to develop and evaluate aircraft and flight management system technology concepts that will benefit conventional take off and landing operations in the terminal area. Emphasis is placed on the development of operating methods for the highly automated environment anticipated in the future. The program involves analyses, simulation, and flight experiments. Flight experiments are conducted using a modified Boeing 737 airplane equipped with highly flexible display and control equipment and an aft flight deck for research purposes. The experimental systems of the Boeing 737 are described including the flight control computer systems, the navigation/guidance system, the control and command panel, and the electronic display system. The ground based facilities used in the program are described including the visual motion simulator, the fixed base simulator, the verification and validation laboratory, and the radio frequency anechoic facility.

1980-01-01

76

Performance of the ATLAS resistive plate chambers  

NASA Astrophysics Data System (ADS)

An overview and results of the effort to monitor and measure the relevant quantities of the Resistive Plate Chamber detectors are presented, addressing in particular three aspects. First, the full exploitation of the high-precision tracking provided by ATLAS Monitored Drift Tubes when measuring the performance of the RPCs. Second, the use of a dedicated data stream to achieve the required statistics. Last, the central role of GRID facilities in providing the necessary computing resources.

Cattani, Giordano; ATLAS Muon Collaboration

2012-01-01

77

Automated Electrostatics Environmental Chamber  

NASA Technical Reports Server (NTRS)

The Mars Electrostatics Chamber (MEC) is an environmental chamber designed primarily to create atmospheric conditions like those at the surface of Mars to support experiments on electrostatic effects in the Martian environment. The chamber is equipped with a vacuum system, a cryogenic cooling system, an atmospheric-gas replenishing and analysis system, and a computerized control system that can be programmed by the user and that provides both automation and options for manual control. The control system can be set to maintain steady Mars-like conditions or to impose temperature and pressure variations of a Mars diurnal cycle at any given season and latitude. In addition, the MEC can be used in other areas of research because it can create steady or varying atmospheric conditions anywhere within the wide temperature, pressure, and composition ranges between the extremes of Mars-like and Earth-like conditions.

Calle, Carlos; Lewis, Dean C.; Buchanan, Randy K.; Buchanan, Aubri

2005-01-01

78

A vacuum chamber feedthrough  

NASA Technical Reports Server (NTRS)

Simple and inexpensive microwave feedthrough has been designed which transfers 130 ns, 5kV pulse into vacuum chamber. Feedthrough may be used over wide range and is adaptable to most coaxial cables, since either multistrand or single strand center conductor cable can be used.

Brown, V. D.

1973-01-01

79

Secondary emission gas chamber  

E-print Network

For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

In'shakov, V; Skvortsov, V

2014-01-01

80

Bubble Chamber Site  

NSDL National Science Digital Library

This substantial site features a large number of photos of bubble chamber (BC) tracks, many with a discussion of the physics. There is a description of how the BC works and also useful tutorial on reading BC pictures. The high quality of the images and the explanations of the events that are shown make this site especially valuable.

2006-06-19

81

Improved wire chamber  

DOEpatents

An improved gas mixture for use with proportional counter devices, such as Geiger-Mueller tubes and drift chambers. The improved gas mixture provides a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor. 2 figs.

Atac, M.

1987-05-12

82

Vacuum Chamber Design of NSLS-II Storage Ring  

SciTech Connect

National Synchrotron Light Source II (NSLS II) will be a 3-GeV, 792-meter circumference, 3rd generation synchrotron radiation facility, with ultra low emittance and extremely high brightness. the storage ring has 30 Double-Bend-Achromatic (DBA) cells. in each cell, there are five magnets and chamber girders, and one straight section for insertion devices or Radio Frequency (RF) cavities or injection. Most vacuum chambers are made from extruded aluminum with two different cross sections: one fitted in the dipole magnets, and the other surrounded by multipole magnets. They discuss the layout of the DBA cells, the detailed design of the cell's vacuum chambers, the mounting of the Beam-Position-Monitor (BPM) buttons, discrete absorbers, lumped pumps and the distributed Non-Evaporable Getter (NEG) strips, and describe the fabrication and testing of these prototype cell chambers. The account also details the development of the chamber bakeout process, the NEG stri's supports, and the RF shielded bellows.

Doom,L.; Ferreira, M.; Hseuh, H. C.; Lincoln, F.; Longo, C.; Ravindranath, V.; Sharma, S.

2008-06-11

83

Combustor with fuel preparation chambers  

NASA Technical Reports Server (NTRS)

An annular combustor having fuel preparation chambers mounted in the dome of the combustor. The fuel preparation chamber comprises an annular wall extending axially from an inlet to an exit that defines a mixing chamber. Mounted to the inlet are an air swirler and a fuel atomizer. The air swirler provides swirled air to the mixing chamber while the atomizer provides a fuel spray. On the downstream side of the exit, the fuel preparation chamber has an inwardly extending conical wall that compresses the swirling mixture of fuel and air exiting the mixing chamber.

Zelina, Joseph (Inventor); Myers, Geoffrey D. (Inventor); Srinivasan, Ram (Inventor); Reynolds, Robert S. (Inventor)

2001-01-01

84

Multi-chamber deposition system  

DOEpatents

A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

Jacobson, Richard L. (Roseville, MN); Jeffrey, Frank R. (Shoreview, MN); Westerberg, Roger K. (Cottage Grove, MN)

1989-10-17

85

Multi-chamber deposition system  

DOEpatents

A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

Jacobson, Richard L. (Roseville, MN); Jeffrey, Frank R. (Shoreview, MN); Westerberg, Roger K. (Cottage Grove, MN)

1989-06-27

86

Three chamber negative ion source  

DOEpatents

A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA); Hiskes, John R. (Livermore, CA)

1985-01-01

87

Wire chamber gases  

SciTech Connect

In this paper, we describe new developments in gas mixtures which have occurred during the last 3--4 years. In particular, we discuss new results on the measurement and modeling of electron drift parameters, the modeling of drift chamber resolution, measurements of primary ionization and the choice of gas for applications such as tracking, single electron detection, X-ray detection and visual imaging. In addition, new results are presented on photon feedback, breakdown and wire aging.

Va'vra, J.

1992-04-01

88

Digital optical spark chambers  

SciTech Connect

The authors have constructed and tested a prototype digital readout system for optical spark chambers using a linear, solid state (CCD) detector array. Position resolution of 0.013 mm (sigma) over a 25 centimeter field of view has been demonstrated. This technique should permit the construction of economical, light weight and low power trajectory hodoscopes for use in cosmic ray instrumentation on balloons and in spacecraft.

Evenson, P.; Tuska, E.

1989-02-01

89

Vibrating-chamber levitation systems  

NASA Technical Reports Server (NTRS)

Systems are described for the acoustic levitation of objects, which enable the use of a sealed rigid chamber to avoid contamination of the levitated object. The apparatus includes a housing forming a substantially closed chamber, and means for vibrating the entire housing at a frequency that produces an acoustic standing wave pattern within the chamber.

Barmatz, M. B.; Granett, D.; Lee, M. C. (inventors)

1985-01-01

90

Vertical two chamber reaction furnace  

DOEpatents

A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

Blaugher, R.D.

1999-03-16

91

Winged reentrant electromagnetic combustion chamber  

Microsoft Academic Search

An internal combustion engine combustion chamber suitable for electromagnetic stimulation of combustion which has been improved by the addition of combustion chamber periphery extensions (wings) filled with dielectric material. The wing dimensions and filler dielectric material are chosen to allow for specification of the chamber EM resonant frequency, preferably at a frequency in the UHF range (where low cost DC

M. A. V

1985-01-01

92

Multi-anode ionization chamber  

DOEpatents

The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

2010-12-28

93

Review of wire chamber aging  

SciTech Connect

This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs.

Va'Vra, J.

1986-02-01

94

NVH at MTUNVH at MTU Presented by  

E-print Network

Chamber Anechoic Chamber #12;FacilitiesFacilities Classroom and Project Area Sound Quality Lab #12.Lab ME'Scope Smart Office O1 dB, dBfa software Matlab, Labview Catia, Ideas, Abacus MSC Nastran MTS Sound ProjectsSample Projects Various projects on sound quality of power seat adjusters, power windows, power

Rao, Mohan

95

Automated protein crystal growth facility  

NASA Technical Reports Server (NTRS)

A customer for the protein crystal growth facility fills the specially designed chamber with the correct solutions, fills the syringes with their quenching solutions, and submits the data needed for the proper growth of their crystal. To make sure that the chambers and syringes are filled correctly, a NASA representative may assist the customer. The data needed is the approximate growth time, the growth temperature, and the desired crystal size, but this data can be changed anytime from the ground, if needed. The chambers are gathered and placed into numbered slots in special drawers. Then, data is entered into a computer for each of the chambers. Technicians map out when each chamber's growth should be activated so that all of the chambers have enough time to grow. All of this data is up-linked to the space station when the previous growth session is over. Anti-vibrational containers need to be constructed for the high forces encountered during the lift off and the landing of the space shuttle, and though our team has not designed these containers, we do not feel that there is any reason why a suitable one could not be made. When the shuttle reaches the space station, an astronaut removes a drawer of quenched chambers from the growth facility and inserts a drawer of new chambers. All twelve of the drawers can be replaced in this fashion. The optical disks can also be removed this way. The old drawers are stored for the trip back to earth. Once inside the growth facility, a chamber is removed by the robot and placed in one of 144 active sites at a time previously picked by a technician. Growth begins when the chamber is inserted into an active site. Then, the sensing system starts to determine the size of the protein crystal. All during the crystal's growth, the customer can view the crystal and read all of the crystal's data, such as growth rate and crystal size. When the sensing system determines that the crystal has reached the predetermined size, the robot is told to pick up a syringe filled with the correct quenchant solution and inject it into the chamber to stop the crystal growth. The chamber is then removed from the active site and placed into its original storage slot. Another chamber is then placed into the active site and the process is repeated in all of the active sites until all of the chambers have complted their growth. After ninety days (the scheduled time between shuttle visits), the crystal growth is completed, and the old drawers are replaced with new ones. Once the customer extracts the crystals, the chambers are retrieved for future customers.

Donald, Stacey

1994-01-01

96

Initial Back-to-Back Fission Chamber Testing in ATRC  

SciTech Connect

Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to provide calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.

Benjamin Chase; Troy Unruh; Joy Rempe

2014-06-01

97

A 'breadboard' biomass production chamber for CELSS  

NASA Technical Reports Server (NTRS)

The Breadboard Project of the Controlled Ecological Life Support System (CELSS) Program is the first attempt by NASA to integrate the primary components of a bioregenerative life support system into a functioning system. The central component of this project is a Biomass Production Chamber (BPC). The BPC is under construction, and when finished will be sealed for the study of the flux of gases, liquids, and solids through the production module of a CELSS. Features of the CELSS breadboard facility will be covered as will design requirements for the BPC. Cultural practices developed for wheat for the BPC wil be discussed.

Prince, Ralph P.; Knott, William M., III; Hilding, Suzanne E.; Mack, Tommy L.

1987-01-01

98

14. VIEW OF VACUUM COATING CHAMBER. THE SYSTEM USED TITANIUM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. VIEW OF VACUUM COATING CHAMBER. THE SYSTEM USED TITANIUM VAPORS TO DEPOSIT TITANIUM COATING ONTO URANIUM PARTS UNDER A VACUUM. (1/11/83) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

99

OUTDOOR SMOG CHAMBER EXPERIMENTS TO TEST PHOTOCHEMICAL MODELS: PHASE 2  

EPA Science Inventory

The smog chamber facility of the University of North Carolina was used to provide experimental data for developing and testing kinetic mechanisms of photochemical smog formation. In this study, 128 pairs of experiments were performed using NOx and various hydrocarbons and hydroca...

100

Overview of the ICF 1000 MJ experiment chamber design  

SciTech Connect

A conceptual design of an experiment chamber for a high gain ICF facility (1000 MJ) is being developed. Performance goals have been established. Several design approaches are being evaluated through computer simulation, engineering analysis, and experimental testing of candidate first wall components. 10 refs., 3 figs.

Slaughter, D.

1988-09-23

101

13. VIEW OF VACUUM CHAMBER AND WELDING EQUIPMENT IN MODULE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. VIEW OF VACUUM CHAMBER AND WELDING EQUIPMENT IN MODULE E. PARTS WERE WELDED UNDER A VACUUM TO PREVENT CORROSION. (11/6/73) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

102

Iran Chamber Society  

NSDL National Science Digital Library

In 2001, the Iran Chamber Society was created in order to provide a non-partisan, non-commercial, comprehensive source of information on Iran. The website's "About Us" section states that their aim is to "create a global awareness about Iranian society and eradicate the misunderstandings and misconceptions about Iranian society, and to play an educational role as well." Visitors will find the website divided up into "Art and Culture", "History", "Society" and "Iran's Guide". The "Exhibitions and Conferences" link on the right side of the homepage leads visitors to a number of exhibitions, including the fascinating "Artistic Murals of Tehran's Metro Stations", which offers a dozen pictures of the beautifully handcrafted murals made of pottery, metal, cement and other materials. The "History" section offers pictures and documents, including some disturbing graphic photos from the Iran-Iraq War in 1980-1988 that appear at the end of the Historic Periods and Events section.

103

Mush Column Magma Chambers  

NASA Astrophysics Data System (ADS)

Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior of the system, coupled with these processes, define the fundamental compositional and dynamic diversity of the Mush Column. In some ways it functions like a complex musical instrument. Entrainment, transport, and sorting of cumulate crystals as a function of repose time and the local flux intensity also contribute to the basic compositional diversity of the system. In the Ferrar dolerite system, about 104 km3 of dolerite is distributed throughout a fir-tree like stack of 4 or 5 extensive 300-750 m thick sills. The lowest sill contains a vast tongue of entrained orthopyroxene (opx) cumulates emplaced with the sill itself. The bulk sill composition varies from 20 pc MgO in the tongue center to 7 pc in the leading tip and margins of the sill, which itself defines the compositional spectrum of the whole complex and is remarkably similar to that exhibited by Hawaii. Relative sorting of large (1-50 mm) opx and small (1-3 mm) plagioclase due to kinetic sieving in the tongue produces pervasive anorthosite stringers. Through local ponding this has culminated in the formation of a small, well-formed layered intrusion consisting of alternating layers of orthopyroxenite and anorthosite. Upwards in the system the sills become progressively depleted in MgO and temporally and spatially contiguous flood basalts are low MgO tholeiites with no sign of opx cumulates. The size, extent, number of sills, and the internal structure of individual sills suggest a rhythm of injection similar to that of volcanic episodes. The continued horizontal stretching of a system of this type would lead to processes as recorded by ophiolites, and the repeated injection into a single reservoir would undoubtedly lead to a massive layered intrusion or to a series of high-level nested plutons.

Marsh, B. D.

2002-12-01

104

Portable electron beam weld chamber  

NASA Technical Reports Server (NTRS)

Development and characteristics of portable vacuum chamber for skate type electron beam welding are discussed. Construction and operational details of equipment are presented. Illustrations of equipment are provided.

Lewis, J. R.; Dimino, J. M.

1972-01-01

105

40 CFR 160.45 - Test system supply facilities.  

Code of Federal Regulations, 2013 CFR

...shall be provided. As specified in the protocol, these include: (1) Facilities for holding, culturing, and maintaining algae and aquatic plants. (2) Facilities for plant growth, including, but not limited to greenhouses, growth chambers,...

2013-07-01

106

40 CFR 160.45 - Test system supply facilities.  

Code of Federal Regulations, 2012 CFR

...shall be provided. As specified in the protocol, these include: (1) Facilities for holding, culturing, and maintaining algae and aquatic plants. (2) Facilities for plant growth, including, but not limited to greenhouses, growth chambers,...

2012-07-01

107

40 CFR 160.45 - Test system supply facilities.  

...shall be provided. As specified in the protocol, these include: (1) Facilities for holding, culturing, and maintaining algae and aquatic plants. (2) Facilities for plant growth, including, but not limited to greenhouses, growth chambers,...

2014-07-01

108

40 CFR 160.45 - Test system supply facilities.  

Code of Federal Regulations, 2011 CFR

...shall be provided. As specified in the protocol, these include: (1) Facilities for holding, culturing, and maintaining algae and aquatic plants. (2) Facilities for plant growth, including, but not limited to greenhouses, growth chambers,...

2011-07-01

109

HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF PLENUM WITH ATTACHED DRAFT REGULATOR. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

110

BOREAS TGB-1/TGB-3 CH4 Chamber Flux Data over the NSA Fen  

NASA Technical Reports Server (NTRS)

The BOREAS TGB-3 team collected methane (CH4) chamber flux measurements at the NSA fen site during May-September 1994 and June-October 1996. Gas samples were extracted approximately every 7 days from chambers and analyzed at the NSA lab facility. The data are provided in tabular ASCII files.

Bubier, Jill L.; Moore, Tim R.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

111

ECRB REFUGE CHAMBER  

SciTech Connect

The purpose of this calculation is to identify the initial design requirements for refuge stations, including the client requirements, standards, codes, laws, and regulations, general discipline design criteria, and design basis events and hazards. The scope of this document is for the specific task of designing and constructing refuge stations in the Enhanced Characterization Repository Block (ECRB) subsurface openings as necessary personnel safety enhancements to the current construction, maintenance and testing operations. This document is for the construction at the Exploratory Site Facility (ESF). The criteria is not intended to be incorporated into the proposed repository design and does not support Site Recommendation or License Application efforts. This calculation is prepared in accordance with N-3.12Q as a field support calculation and was prepared using the ''Technical Work Plan for Test Facilities Design FY01 Work Activities'' (TWP) (CRWMS M&O 2000b).

J. W. Keifer

2001-12-03

112

Ion chamber based neutron detectors  

SciTech Connect

A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

2014-12-16

113

Anterior chamber depth during hemodialysis  

PubMed Central

Background Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD) because of anterior chamber depth changes during this therapy. Purpose To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results There was no difference in the axial length between the three measurements (P = 0.241). We observed a significantly decreased anterior chamber depth (P = 0.002) during HD sessions. Conclusion Our results support the idea that there is a change in anterior chamber depth in HD sessions. PMID:23976841

Gracitelli, Carolina Pelegrini Barbosa; Stefanini, Francisco Rosa; Penha, Fernando; Góes, Miguel Ângelo; Draibe, Sérgio Antonio; Canziani, Maria Eugênia; Junior, Augusto Paranhos

2013-01-01

114

Proton beam monitor chamber calibration.  

PubMed

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences-of the order of 3%-were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth-i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers-rather than cylindrical chambers-for the reference dosimetry of pseudo-monoenergetic proton beams. PMID:25109620

Gomà, C; Lorentini, S; Meer, D; Safai, S

2014-09-01

115

Proton beam monitor chamber calibration  

NASA Astrophysics Data System (ADS)

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams.

Gomà, C.; Lorentini, S.; Meer, D.; Safai, S.

2014-09-01

116

Regional Chamber of Commerce, Roanoke Regional Chamber of  

E-print Network

Chamber of Commerce, and NewVa Corridor Technology Center ­ is the name of the group that developed ­ America's 6-year-old celebration of books and reading ­ came to Patrick County in March. Poet Emily

Virginia Tech

117

Electromagnetic propulsion test facility  

NASA Technical Reports Server (NTRS)

A test facility for the exploration of electromagnetic propulsion concept is described. The facility is designed to accommodate electromagnetic rail accelerators of various lengths (1 to 10 meters) and to provide accelerating energies of up to 240 kiloJoules. This accelerating energy is supplied as a current pulse of hundreds of kiloAmps lasting as long as 1 millisecond. The design, installation, and operating characteristics of the pulsed energy system are discussed. The test chamber and its operation at pressures down to 1300 Pascals (10 mm of mercury) are described. Some aspects of safety (interlocking, personnel protection, and operating procedures) are included.

Gooder, S. T.

1984-01-01

118

Ames Hybrid Combustion Facility  

NASA Technical Reports Server (NTRS)

The report summarizes the design, fabrication, safety features, environmental impact, and operation of the Ames Hybrid-Fuel Combustion Facility (HCF). The facility is used in conducting research into the scalability and combustion processes of advanced paraffin-based hybrid fuels for the purpose of assessing their applicability to practical rocket systems. The facility was designed to deliver gaseous oxygen at rates between 0.5 and 16.0 kg/sec to a combustion chamber operating at pressures ranging from 300 to 900. The required run times were of the order of 10 to 20 sec. The facility proved to be robust and reliable and has been used to generate a database of regression-rate measurements of paraffin at oxygen mass flux levels comparable to those of moderate-sized hybrid rocket motors.

Zilliac, Greg; Karabeyoglu, Mustafa A.; Cantwell, Brian; Hunt, Rusty; DeZilwa, Shane; Shoffstall, Mike; Soderman, Paul T.; Bencze, Daniel P. (Technical Monitor)

2003-01-01

119

An altitude chamber rescue ensemble  

NASA Technical Reports Server (NTRS)

Altitude chamber tests accomplished with the astronaut crews in the spacecraft at a simulated altitude of above 200,000 ft requires that a rescue team be provided in the event of an accident in the spacecraft. The rescue crew is stationed in an airlock maintained at an altitude of 18,000 ft. A protective ensemble provides the rescue crew with life support capabilities, communications, and protection in the event of an emergency. In the event of an emergency, repressurization of the chamber is initiated; as the chamber descends, the airlock ascends and the two meet at 25,000 ft. This phase of the emergency repressurization takes less than 30 sec.

Lloyd, R. P.

1972-01-01

120

Ultraviolet laser calibration of drift chambers  

E-print Network

We demonstrate the use of a focused ultraviolet laser as a track calibration source in drift chambers, and specifically in a small time projection chamber (TPC). Drift chambers such as TPCs reconstruct the trajectories of ...

Elliott, Grant (Grant Andrew)

2006-01-01

121

Extra Terrestrial Environmental Chamber Design  

NASA Technical Reports Server (NTRS)

A vacuum chamber designed to simulate the dusty environment on the Moon or Mars has been built for Goddard Space Flight Center. The path from concept to delivery is reviewed, with lessons learned and pitfalls highlighted along the way.

Hughes, David W.

2008-01-01

122

Cyclically controlled welding purge chamber  

NASA Technical Reports Server (NTRS)

An arrangement for butt-welding cylindrical sections of large, thin-wall tanks includes a rotatable mandrel with side-by-side sets of radial position adjusters. Each set of adjusters bears on one of the tank sections adjacent the seam, to prevent the sections from sagging out-of-round. The mandrel rotates relative to the welder, so that a continuous seam is formed. A purge chamber is fixed in position behind the seam at the weld head, and is flushed with inert gas. The purge chamber includes a two-sided structure which is contiguous with the cylindrical sections and a circumferential vane to form an open-ended tube-like structure, through which the radial position adjusters pass as the mandrel and cylindrical workpiece sections rotate. The tube-like structure is formed into a chamber by a plurality of movable gates which are controlled to maintain a seal while allowing adjusters to progress through the purge chamber.

Gallagher, Robert L. (Inventor)

1996-01-01

123

21 CFR 866.2120 - Anaerobic chamber.  

Code of Federal Regulations, 2010 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

2010-04-01

124

21 CFR 866.2120 - Anaerobic chamber.  

Code of Federal Regulations, 2012 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a...

2012-04-01

125

Light diffusing fiber optic chamber  

DOEpatents

A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

Maitland, Duncan J. (Lafayette, CA)

2002-01-01

126

Numerical grid generation and flow simulation in SSME thrust chamber  

SciTech Connect

The development of liquid and solid rocket engines for future space projects demands a detailed optimization process for highly efficient performance and cost reasons. Also, testing of full size engines may not be feasible when the large size requires test facilities which are cost prohibitive or if vacuum operation cannot be acquired. For such situations only scaling from small test scale measurements or accurate analytical predictions will provide the performance prior to actually flying the mission. A rigorous approach for simulating the combustion processes in liquid rocket engines by employing a direct solution of Navier-Stokes equations within the entire volume of the thrust chambers is presented. This method is illustrated in the solution of reactive flow in the Space Shuttle Main Engine (SSME) thrust chamber. The objective is to review recent improvements in the mathematical model and to present the grid generation methodology suitable for rocket thrust chamber geometries.

Gross, K.W.; Daley, P.L.; Przekwas, A.J.

1987-01-01

127

Spectra, composition, and interactions of nuclei with magnet interaction chambers  

NASA Technical Reports Server (NTRS)

Emulsion chambers will be flown in the Astromag Facility to measure the cosmic ray composition and spectra to 10 exp 15 eV total energy and to definitively study the characteristics of nucleus-nucleus interactions above 10 exp 12 eV/n. Two configurations of emulsion chambers will be flown in the SCIN/MAGIC experiment. One chamber has an emulsion target and a calorimeter similar to those recently flown on balloons for composition and spectra measurements. The other has an identical calorimeter and a low-density target section optimized for performing rigidity measurements on charged particles produced in interactions. The transverse momenta of charged and neutral mesons, direct hadronic pairs from resonance decays and interference effects, and possible charge clustering in high-density states of matter will be studied.

Parneil, T. A.; Derrickson, J. H.; Fountain, W. F.; Roberts, F. E.; Tabuki, T.; Watts, J. W.; Burnett, T. H.; Cherry, M. C.; Dake, S.; Fuki, M.

1990-01-01

128

RADIATION ENVIRONMENT OF GROWTH CHAMBERS  

EPA Science Inventory

Radiation measurements with different types of meters in several controlled environment facilities have been compiled to demonstrate the problems associated with insuring uniform radiation levels in separate facilities. Data are provided for a quantum meter, three photometers, a ...

129

Evaluation of Impinging Stream Vortex Chamber Concepts for Liquid Rocket Engine Applications  

NASA Technical Reports Server (NTRS)

To pursue technology developments for future launch vehicles, NASA/Marshall Space Flight Center (MSFC) is examining vortex chamber concepts for liquid rocket engine applications. Past studies indicated that the vortex chamber schemes potentially have a number of advantages over conventional chamber methods. Due to the nature of the vortex flow, relatively cooler propellant streams tend to flow along the chamber wall. Hence, the thruster chamber can be operated without the need of any cooling techniques. This vortex flow also creates strong turbulence, which promotes the propellant mixing process. Consequently, the subject chamber concepts not only offer system simplicity, but also enhance the combustion performance. Test results have shown that chamber performance is markedly high even at a low chamber length-to-diameter ratio (LD). This incentive can be translated to a convenience in the thrust chamber packaging. Variations of the vortex chamber concepts have been introduced in the past few decades. These investigations include an ongoing work at Orbital Technologies Corporation (ORBITEC). By injecting the oxidizer tangentially at the chamber convergence and fuel axially at the chamber head end, Knuth et al. were able to keep the wall relatively cold. A recent investigation of the low L/D vortex chamber concept for gel propellants was conducted by Michaels. He used both triplet (two oxidizer orifices and one fuel orifice) and unlike impinging schemes to inject propellants tangentially along the chamber wall. Michaels called the subject injection scheme an Impinging Stream Vortex Chamber (ISVC). His preliminary tests showed that high performance, with an Isp efficiency of 9295, can be obtained. MSFC and the U. S. Army are jointly investigating an application of the ISVC concept for the cryogenic oxygen/hydrocarbon propellant system. This vortex chamber concept is currently tested with gel propellants at AMCOM at Redstone Arsenal, Alabama. A version of this concept for the liquid oxygen (LOX) hydrocarbon fuel (RP-1) system has been derived from the one for the gel propellant. An unlike impinging injector was employed to deliver the propellants to the chamber. MSFC is also conducting an alternative injection scheme, called the chasing injector, associated with this vortex chamber concept. In this injection technique, both propellant jets and their impingement point are in the same chamber cross-sectional plane. Long duration tests (approximately up to 15 seconds) will be conducted on the ISVC to study the thermal effects. This paper will report the progress of the subject efforts at NASA Marshall Space Flight Center. Thrust chamber performance and thermal wall compatibility will be evaluated. The chamber pressures, wall temperatures, and thrust will be measured as appropriate. The test data will be used to validate CFD models, which, in turn, will be used to design the optimum vortex chambers. Measurements in the previous tests showed that the chamber pressures vary significantly with radius. This is due to the existence of the vortices in the chamber flow field. Hence, the combustion efficiency may not be easily determined from chamber pressure. For this project, measured thrust data will be collected. The performance comparison will be in terms of specific impulse efficiencies. In addition to the thrust measurements, several pressure and temperature readings at various locations on the chamber head faceplate and the chamber wall will be made. The first injector and chamber were designed and fabricated based on the available data and experience gained during gel propellant system tests by the U.S. Army. The alternate injector for the ISVC was also fabricated. Hot-fire tests of the vortex chamber are about to start and are expected to complete in February of 2003 at the TS115 facility of MSFC.

Trinh, Huu P.; Bullard, Brad; Kopicz, Charles; Michaels, Scott

2002-01-01

130

Recent Enhancements to the NASA Langley Structural Acoustics Loads and Transmission (SALT) Facility  

NASA Technical Reports Server (NTRS)

The Structural Acoustics Loads and Transmission (SALT) facility at the NASA Langley Research Center is comprised of an anechoic room and a reverberant room, and may act as a transmission loss suite when test articles are mounted in a window connecting the two rooms. In the latter configuration, the reverberant room acts as the noise source side and the anechoic room as the receiver side. The noise generation system used for qualification testing in the reverberant room was previously shown to achieve a maximum overall sound pressure level of 141 dB. This is considered to be marginally adequate for generating sound pressure levels typically required for launch vehicle payload qualification testing. Recent enhancements to the noise generation system increased the maximum overall sound pressure level to 154 dB, through the use of two airstream modulators coupled to 35 Hz and 160 Hz horns. This paper documents the acoustic performance of the enhanced noise generation system for a variety of relevant test spectra. Additionally, it demonstrates the capability of the SALT facility to conduct transmission loss and absorption testing in accordance with ASTM and ISO standards, respectively. A few examples of test capabilities are shown and include transmission loss testing of simple unstiffened and built up structures and measurement of the diffuse field absorption coefficient of a fibrous acoustic blanket.

Rizzi, Stephen A.; Cabell, Randolph H.; Allen, Albert R.

2013-01-01

131

Directive Wavefronts Inside a Time Reversal Electromagnetic Chamber  

E-print Network

to verify the radiated-immunity of equipments such as transverse electromagnetic (TEM) and gigahertz TEM cells [1], used for immunity testing with TEM fields. Also, the use of anechoic and semi that testing in an AC may lead to stress levels of electronic components inside the equipment that are 10-15 d

Boyer, Edmond

132

Iridium-Coated Rhenium Combustion Chamber  

NASA Technical Reports Server (NTRS)

Iridium-coated rhenium combustion chamber withstands operating temperatures up to 2,200 degrees C. Chamber designed to replace older silicide-coated combustion chamber in small rocket engine. Modified versions of newer chamber could be designed for use on Earth in gas turbines, ramjets, and scramjets.

Schneider, Steven J.; Tuffias, Robert H.; Rosenberg, Sanders D.

1994-01-01

133

Internal combustion engine with rotary combustion chamber  

Microsoft Academic Search

This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means has an air and fuel intake passage, and exhaust gas passage,

C. N. Hansen; P. C. Cross

1986-01-01

134

Internal combustion engine with rotary combustion chamber  

Microsoft Academic Search

This patent describes an internal combustion engine comprising: a block having at least one cylindrical wall surrounding a piston chamber, piston means located in the piston chamber, means operable to reciprocate the piston means in the chamber, head means mounted on the block covering the chamber. The head means having an air and fuel intake passage, an exhaust gas passage,

C. N. Hansen; P. C. Cross

1988-01-01

135

The LIFE Dynamic Chamber System  

NASA Astrophysics Data System (ADS)

Dry-wall IFE designs such as LIFE utilize Xe fill gas to protect the target chamber first wall from x-ray heating and ionic debris. A key question is how cool, settled and clean the Xe must be to permit beam propagation and target transport, and how to reach this state at a 10+ Hz shot repetition rate. Xe is at low density in the target chamber, and purified Xe is reinjected at higher density and lower temperature into the larger outer chamber. Maintenance of this density difference due to blast waves generated by implosion of the target capsules is being assessed with HYDRA and 3D VTF, and possible validation experiments are being investigated. Detailed gas response near the wall is being studied using 3D Miranda. A laboratory-scale theta pinch experiment will study cooling and beam propagation in Xe.

Rhodes, Mark; Kane, Jave; Latkowski, Jeffery; Cook, Andrew; Divol, Laurent; Loosmore, Gwendolen; Scott, Howard; Scullard, Christian; Tabak, Max; Wilks, Scott; Moses, Gregory; Heltemes, Thad; Sacks, Ryan; Pantano, Carlos; Kramer, Richard

2011-11-01

136

Annular-Cross-Section CFE Chamber  

NASA Technical Reports Server (NTRS)

Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

Sharnez, Rizwan; Sammons, David W.

1994-01-01

137

Computational model to configure the AEDC 7V chamber optical system and to simulate the measured optical performance  

Microsoft Academic Search

Refurbishment of the Arnold Engineering Development Center (AEDC) 7V high-vacuum cryogenic chamber has recently been completed. This chamber now provides a high-fidelity ground calibration and test facility for infrared surveillance sensors and infrared seekers. Although the chamber optical system was originally designed for diffraction-limited performance in the MWIR to LWIR wavebands, its actual performance allows near diffraction-limited testing into the

James D. Selman

1995-01-01

138

Hydrostatic Hyperbaric Chamber Ventilation System  

NASA Technical Reports Server (NTRS)

The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications, including the treatment of medical conditions. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy available in the developing world for the treatment of a variety of medical conditions. Specifically, hyperbaric oxygen therapy is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. Hyperbaric oxygen therapy is simply too expensive and too dangerous to implement in the developing world using standard equipment. The hydrostatic hyperbaric chamber technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system that will provide controlled pressurization of the system, and provide adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware, supports sustainability.

Sargusingh, Miriam M.

2011-01-01

139

Gas-Grain Simulation Facility (GGSF)  

NASA Technical Reports Server (NTRS)

The goal of the Gas-Grain Simulation Facility project is to provide a microgravity laboratory to facilitate research relevant to exobiology (the study of the origin and evolution of life in the universe). Such a facility will also be useful in other areas of study important to NASA including planetary science, biology, atmospheric science, astrophysics, chemistry, and physics. To achieve this goal, the project will develop and support the GGSF, a modular facility-class payload planned for inclusion on Space Station Freedom. The GGSF will consist of the following: an experiment chamber(s) supported by subsystems that provide chamber environment regulation and monitoring capabilities; sample generation, injection, positioning, and retrieval capabilities; and computer control, data acquisition, and housekeeping capabilities. The facility will also provide analytical tools such as light-scattering measurement systems, aerosol size-spectrum measurement devices, and optical imaging systems.

Greenwald, Ken

1992-01-01

140

Ionization Chamber Measures Extreme Ultraviolet  

NASA Technical Reports Server (NTRS)

Ionization chamber operates in nearly total photon absorption as stable, self-calibrating detector of ionizing extreme ultraviolet radiation. Working gas of instrument is neon; photoionization properties well known and readily applicable to absolute measurements. Designed for measurements of solar ultraviolet flux aboard sounding rocket, instrument used on Earth to measure ultraviolet radiation in vacuum systems. Ionization chamber collects positive neon ions and electrons produced by irradiation of neon gas by ultraviolet photons. Approximately one ion produced by each photon; consequently, photoionization current nearly proportional to photon flux.

Carlson, Robert W.

1987-01-01

141

Lightweight Chambers for Thrust Assemblies  

NASA Technical Reports Server (NTRS)

The Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration (NASA) has successfully applied new materials and fabrication techniques to create actively cooled thrust chambers that operate 200-400 degrees hotter and weigh 50% lighter than conventional designs. In some vehicles, thrust assemblies account for as much as 20% of the engine weight. So, reducing the weight of these components and increasing their operating range will benefit many engines and vehicle designs, including Reusable Launch Vehicle (RLV) concepts. Obviously, copper and steel alloys have been used successfully for many years in the chamber components of thrust assemblies. Yet, by replacing the steel alloys with Polymer Matrix Composite (PMC) and/or Metal Matrix Composite (MMC) materials, design weights can be drastically reduced. In addition, replacing the traditional copper alloys with a Ceramic Matrix Composite (CMC) or an advanced copper alloy (Cu-8Cr-4Nb, also known as GRCop-84) significantly increases allowable operating temperatures. Several small MMC and PMC demonstration chambers have recently been fabricated with promising results. Each of these designs included GRCop-84 for the cooled chamber liner. These units successfully verified that designs over 50% lighter are feasible. New fabrication processes, including advanced casting technology and a low cost vacuum plasma spray (VPS) process, were also demonstrated with these units. Hot-fire testing at MSFC is currently being conducted on the chambers to verify increased operating temperatures available with the GRCop-84 liner. Unique CMC chamber liners were also successfully fabricated and prepared for hot-fire testing. Yet, early results indicate these CMC liners need significantly more development in order to use them in required chamber designs. Based on the successful efforts with the MMC and PMC concepts, two full size "lightweight" chambers are currently being designed and fabricated for hot-fire testing at MSFC in 2001. These "full size" chambers will be similar in size to those used on the X33 engine (RS2200). One will be fabricated with a MMC structural jacket, while the other uses a PMC jacket. Each will be designed for thrust levels of 15,000 pounds in an oxygen/hydrogen environment with liquid hydrogen coolant. Both chambers will use GRCop-84 for its channel wall liner. Each unit is expected to be at least 60% lighter than a conventional design with traditional materials. Hot-fire testing on the full size units in late 2001 will directly compare performance results between a conventional chamber design and these "lightweight" alternatives. The technology developed and demonstrated by this effort will not only benefit next generation RLV programs, but it can be applied to other existing and future engine programs, as well. Efforts were sponsored by the Advanced Space Transportation Program for RLV Focused Technologies. The task team was led by MSFC with additional members from NASA-Glenn Research Center and the Rocketdyne Division of The Boeing Company. Specific materials development and fabrication processes were provided by Aerojet, Lockheed Martin Astronautics, Composite Optics, Inc., Hyper-Therm, Ceramic Composites, Inc., MSE Technology Applications, and Plasma Processes, Inc.

Elam, Sandra K.; Lee, Jonathan; Holmes, Richard; Zimmerman, Frank; Effinger, Mike; Turner, James E. (Technical Monitor)

2001-01-01

142

Space simulation facilities providing a stable thermal vacuum facility  

NASA Technical Reports Server (NTRS)

CBI has recently constructed the Intermediate Thermal Vacuum Facility. Built as a corporate facility, the installation will first be used on the Boost Surveillance and Tracking System (BSTS) program. It will also be used to develop and test other sensor systems. The horizontal chamber has a horseshoe shaped cross section and is supported on pneumatic isolators for vibration isolation. The chamber structure was designed to meet stability and stiffness requirements. The design process included measurement of the ambient ground vibrations, analysis of various foundation test article support configurations, design and analysis of the chamber shell and modal testing of the chamber shell. A detailed 3-D finite element analysis was made in the design stage to predict the lowest three natural frequencies and mode shapes and to identify local vibrating components. The design process is described and the results are compared of the finite element analysis to the results of the field modal testing and analysis for the 3 lowest natural frequencies and mode shapes. Concepts are also presented for stiffening large steel structures along with methods to improve test article stability in large space simulation facilities.

Tellalian, Martin L.

1990-01-01

143

Flow-induced noise from wind tunnel turbulence reduction screens  

Microsoft Academic Search

Boeing is acquiring a new Low Speed Aeroacoustic Facility to simulate low speed flight conditions by adding a free jet to an existing anechoic chamber. The primary facility characteristics will be high flow quality and low background noise levels in the open jet test section. During the design phase, it was recognized that noise generated by flow through the turbulence

Richard M. Allen; Richard R. Gibbs; Patrick J. F. Clark

1987-01-01

144

Multilayer coating facility for the HEFT hard X-ray telescope Carsten P. Jensena  

E-print Network

A planar magnetron sputtering facility has been established at the Danish Space Research Institute (DSRI. The facility is based on a planar magnetron sputtering arrangement. The next section describes the facility. 2. COATING FACILITY The facility is a 0.8 m3 vacuum-chamber (bell-jar) with two planar DC magnetron

145

Nondestructive test of regenerative chambers  

NASA Technical Reports Server (NTRS)

Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

Malone, G. A.; Stauffis, R.; Wood, R.

1972-01-01

146

Drift and proportional tracking chambers  

SciTech Connect

Many techniques have been exploited in constructing tracking chambers, particle detectors which measure the trajectories and momenta of charged particles. The particular features of high-energy interactions - charged particle multiplicities, angular correlations and complex vertex topologies, to name a few - and the experimental environment of the accelerator - event rates, background rates, and so on - accent the importance of certain detector characteristics. In high energy e/sup +/e/sup -/, anti pp and pp interactions the final states are dominated by closely collimated jets of high multiplicity, requiring good track-pair resolution in the tracking chamber. High energy particles deflect very little in limited magnetic field volumes, necessitating good spatial resolution for accurate momentum measurements. The colliding beam technique generally requires a device easily adapted to full solid-angle coverage, and the high event rates expected in some of these machines put a premium on good time resolution. Finally, the production and subsequent decays of the tau, charmed and beautiful mesons will provide multiple vertex topologies. To reconstruct these vertices reliably will require considerable improvements in spatial resolution and track-pair resolution. This lecture considers the proportional counter and its descendant, the drift chamber, as tracking chambers. Its goal is to review the physics of this device in order to understand its performance limitations and promises.

Jaros, J.A.

1980-11-01

147

The TESLA Time Projection Chamber  

E-print Network

A large Time Projection Chamber is proposed as part of the tracking system for a detector at the TESLA electron positron linear collider. Different ongoing R&D studies are reviewed, stressing progress made on a new type readout technique based on Micro-Pattern Gas Detectors.

Nabil Ghodbane

2002-12-12

148

The meditation chamber: a debriefing  

Microsoft Academic Search

During the Emerging Technologies exhibition at Siggraph 2001, over 400 attendees experienced The Meditation Chamber. This immersive, bio-interactive environment was designed to use visual, audio, and tactile cues to create, guide, and maintain a user's guided relaxation and meditation experience. During this sketch, the project's producers will discuss the design and implementation of this unique installation. We will also show

A. Fleming Seay; Diane Gromala; Larry Hodges; Chris Shaw

2002-01-01

149

A molecular beam epitaxy facility for in situ neutron scattering  

SciTech Connect

A molecular beam epitaxy (MBE) facility has been built to enable in situ neutron scattering measurements during growth of epitaxial layers. While retaining the full capabilities of a research MBE chamber, this facility has been optimized for polarized neutron reflectometry measurements. Optimization includes a compact lightweight portable design, a neutron window, controllable magnetic field, deposition across a large 76 mm diameter sample with exceptional flux uniformity, and sample temperatures continuously controllable from 38 to 1375 K. A load lock chamber allows for sample insertion, storage of up to 4 samples, and docking with other facilities. The design and performance of this chamber are described here.

Dura, J. A.; LaRock, J. [NIST Center for Neutron Research, 100 Bureau Dr. MS 6102, Gaithersburg, Maryland 20899 6102 (United States)

2009-07-15

150

Hydrostatic Hyperbaric Chamber Ventilation System  

NASA Technical Reports Server (NTRS)

The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware, supports sustainability.

Sarguisingh, Miriam J.

2012-01-01

151

Test and calibration of large drift tube chambers with cosmic rays  

Microsoft Academic Search

A cosmic ray measurement facility has been set up at Ludwig-Maximilians-University Munich (LMU) and is used at present to commission and calibrate Monitored Drift Tube (MDT) chambers for the muon spectrometer of the ATLAS experiment. Each of these chambers-produced in collaboration with the Max-Planck-Institut fuumlr Physik and the Joint Institute for Nuclear Research in Dubna-consists of 432 drift tubes with

Otmar Biebel; Tim Christiansen; Jörg Dubbert; Johannes Elmsheuser; Frank Fiedler; Ralf Hertenberger; Oliver Kortner; Thomas Nunnemann; Felix Rauscher; Dorothee Schaile; Arnold Staude; Raimund Ströhmer; Balázs Újvári; Cornelius F. Vollmer

2005-01-01

152

Medical devices and procedures in the hyperbaric chamber.  

PubMed

The aim of this paper is to present current controversies concerning the safety of medical devices and procedures under pressure in a hyperbaric chamber including: defibrillation in a multiplace chamber; implantable devices during hyperbaric oxygen treatment (HBOT) and the results of a recent European questionnaire on medical devices used inside hyperbaric chambers. Early electrical defibrillation is the only effective therapy for cardiac arrest caused by ventricular fibrillation or pulseless ventricular tachycardia. The procedure of defibrillation under hyperbaric conditions is inherently dangerous owing to the risk of fire, but it can be conducted safely if certain precautions are taken. Recently, new defibrillators have been introduced for hyperbaric medicine, which makes the procedure easier technically, but it must be noted that sparks and fire have been observed during defibrillation, even under normobaric conditions. Therefore, delivery of defibrillation shock in a hyperbaric environment must still be perceived as a hazardous procedure. Implantable devices are being seen with increasing frequency in patients referred for HBOT. These devices create a risk of malfunction when exposed to hyperbaric conditions. Some manufacturers support patients and medical practitioners with information on how their devices behave under increased pressure, but in some cases an individual risk-benefit analysis should be conducted on the patient and the specific implanted device, taking into consideration the patient's clinical condition, the indication for HBOT and the capability of the HBOT facility for monitoring and intervention in the chamber. The results of the recent survey on use of medical devices inside European hyperbaric chambers are also presented. A wide range of non-CE-certified equipment is used in European chambers. PMID:25596835

Kot, Jacek

2014-12-01

153

Design and testing of a model CELSS chamber robot  

NASA Technical Reports Server (NTRS)

A robot system for use in an enclosed environment was designed and tested. The conceptual design will be used to assist in research performed by the Controlled Ecological Life Support System (CELSS) project. Design specifications include maximum load capacity, operation at specified environmental conditions, low maintenance, and safety. The robot system must not be hazardous to the sealed environment, and be capable of stowing and deploying within a minimum area of the CELSS chamber facility. This design consists of a telescoping robot arm that slides vertically on a shaft positioned in the center of the CELSS chamber. The telescoping robot arm consists of a series of links which can be fully extended to a length equal to the radius of the working envelope of the CELSS chamber. The vertical motion of the robot arm is achieved through the use of a combination ball screw/ball spline actuator system. The robot arm rotates cylindrically about the vertical axis through use of a turntable bearing attached to a central mounting structure fitted to the actuator shaft. The shaft is installed in an overhead rail system allowing the entire structure to be stowed and deployed within the CELSS chamber. The overhead rail system is located above the chamber's upper lamps and extends to the center of the CELSS chamber. The mounting interface of the actuator shaft and rail system allows the entire actuator shaft to be detached and removed from the CELSS chamber. When the actuator shaft is deployed, it is held fixed at the bottom of the chamber by placing a square knob on the bottom of the shaft into a recessed square fitting in the bottom of the chamber floor. A support boot ensures the rigidity of the shaft. Three student teams combined into one group designed a model of the CELSS chamber robot that they could build. They investigated materials, availability, and strength in their design. After the model arm and stand were built, the class performed pre-tests on the entire system. A stability pre-test was used to determine whether the model robot arm would tip over on the stand when it was fully extended. Results showed the stand tipped when 50 Newtons were applied horizontally to the top of the vertical shaft while the arm was fully extended. This proved that it was stable. Another pre-test was the actuator slip test used to determine if there is an adequate coefficient of friction between the actuator drive wheels and drive cable to enable the actuator to fully extend and retract the arm. This pre-test revealed that the coefficient of friction was not large enough to prevent slippage. Sandpaper was glued to the drive wheel and this eliminated the slippage problem. The class preformed a fit test in the CELSS chamber to ensure that the completed robot arm is capable of reaching the entire working envelope. The robot was centered in the chamber and the arm was fully extended to the sides of the chamber. The arm was also able to retract to clear the drain pipes separating the upper and lower plant trays.

Davis, Mark; Dezego, Shawn; Jones, Kinzy; Kewley, Christopher; Langlais, Mike; Mccarthy, John; Penny, Damon; Bonner, Tom; Funderburke, C. Ashley; Hailey, Ruth

1994-01-01

154

Design and testing of a model CELSS chamber robot  

NASA Astrophysics Data System (ADS)

A robot system for use in an enclosed environment was designed and tested. The conceptual design will be used to assist in research performed by the Controlled Ecological Life Support System (CELSS) project. Design specifications include maximum load capacity, operation at specified environmental conditions, low maintenance, and safety. The robot system must not be hazardous to the sealed environment, and be capable of stowing and deploying within a minimum area of the CELSS chamber facility. This design consists of a telescoping robot arm that slides vertically on a shaft positioned in the center of the CELSS chamber. The telescoping robot arm consists of a series of links which can be fully extended to a length equal to the radius of the working envelope of the CELSS chamber. The vertical motion of the robot arm is achieved through the use of a combination ball screw/ball spline actuator system. The robot arm rotates cylindrically about the vertical axis through use of a turntable bearing attached to a central mounting structure fitted to the actuator shaft. The shaft is installed in an overhead rail system allowing the entire structure to be stowed and deployed within the CELSS chamber. The overhead rail system is located above the chamber's upper lamps and extends to the center of the CELSS chamber. The mounting interface of the actuator shaft and rail system allows the entire actuator shaft to be detached and removed from the CELSS chamber. When the actuator shaft is deployed, it is held fixed at the bottom of the chamber by placing a square knob on the bottom of the shaft into a recessed square fitting in the bottom of the chamber floor. A support boot ensures the rigidity of the shaft. Three student teams combined into one group designed a model of the CELSS chamber robot that they could build. They investigated materials, availability, and strength in their design. After the model arm and stand were built, the class performed pre-tests on the entire system. A stability pre-test was used to determine whether the model robot arm would tip over on the stand when it was fully extended. Results showed the stand tipped when 50 Newtons were applied horizontally to the top of the vertical shaft while the arm was fully extended. chamber to ensure that the completed robot arm is capable of reaching the entire working envelope. -The robot was centered in the chamber and the arm was fully extended to the sides of the chamber. The arm was also able to retract to clear the drain pipes separating the upper and lower plant trays.

Davis, Mark; Dezego, Shawn; Jones, Kinzy; Kewley, Christopher; Langlais, Mike; McCarthy, John; Penny, Damon; Bonner, Tom; Funderburke, C. Ashley; Hailey, Ruth

1994-08-01

155

Building a Cloud Chamber (Cosmic Ray Detector)  

NSDL National Science Digital Library

In this activity, students learn about cosmic rays firsthand by building a cloud chamber to detect them. The comprehensive activity includes step-by-step directions for constructing and operating a cloud chamber and ideas for additional experiments.

156

Single wire drift chamber design  

SciTech Connect

This report summarizes the design and prototype tests of single wire drift chambers to be used in Fermilab test beam lines. The goal is to build simple, reliable detectors which require a minimum of electronics. Spatial resolution should match the 300 ..mu..m rms resolution of the 1 mm proportional chambers that they will replace. The detectors will be used in beams with particle rates up to 20 KHz. Single track efficiency should be at least 99%. The first application will be in the MT beamline, which has been designed for calibration of CDF detectors. A set of four x-y modules will be used to track and measure the momentum of beam particles.

Krider, J.

1987-03-30

157

Experimental biomass burning emission assessment by combustion chamber  

NASA Astrophysics Data System (ADS)

Biomass burning is a significant source of several atmospheric gases and particles and it represents an important ecological factor in the Mediterranean ecosystem. In this work we describe the performances of a recently developed combustion chamber to show the potential of this facility in estimating the emission from wildland fire showing a case study with leaves, small branches and litter of two representative species of Mediterranean vegetation, Quercus pubescens and Pinus halepensis. The combustion chamber is equipped with a thermocouple, a high resolution balance, an epiradiometer, two different sampling lines to collect organic volatile compounds (VOCs) and particles, a sampling line connected to a Proton Transfer Reaction Mass-Spectrometer (PTR-MS) and a portable analyzer to measure CO and CO2 emission. VOCs emission were both analyzed with GC-MS and monitored on-line with PTR-MS. The preliminary qualitative analysis of emission showed that CO and CO2 are the main gaseous species emitted during the smoldering and flaming phase, respectively. Many aromatics VOCs as benzene and toluene, and many oxygenated VOC as acetaldehyde and methanol were also released. This combustion chamber represents an important tool to determine the emission factor of each plant species within an ecosystem, but also the contribution to the emissions of the different plant tissues and the kinetics of different compound emissions during the various combustion phases. Another important feature of the chamber is the monitoring of the carbon balance during the biomass combustion.

Lusini, Ilaria; Pallozzi, Emanuele; Corona, Piermaria; Ciccioli, Paolo; Calfapietra, Carlo

2014-05-01

158

Acoustic facilities for human factors research at NASA Langley Research Center: Description and operational capabilities  

NASA Technical Reports Server (NTRS)

A number of facilities were developed which provide a unique test capability for psychoacoustics and related human factors research. The design philosophy, physical layouts, dimensions, construction features, operating capabilities, and example applications for these facilities are described. In the exterior effects room, human subjects are exposed to the types of noises that are experienced outdoors, and in the interior effects room, subjects are exposed to the types of noises and noise-induced vibrations that are experience indoors. Subjects are also exposed to noises in an echo-free environment in the anechoic listening room. An aircraft noise synthesis system, which simulates aircraft flyover noise at an observer position on the ground, is used in conjunction with these three rooms. The passenger ride quality apparatus, a device for studying passenger response to noise and vibration in aircraft, or in other vehicles, is described.

Hubbard, H. H.; Powell, C. A.

1981-01-01

159

MPS II drift chamber system  

SciTech Connect

The MPS II detectors are narrow drift space chambers designed for high position resolution in a magnetic field and in a very high particle flux environment. Central to this implementation was the development of 3 multi-channel custom IC's and one multi-channel hybrid. The system is deadtimeless and requires no corrections on an anode-to-anode basis. Operational experience and relevance to ISABELLE detectors is discussed.

Platner, E.D.

1982-01-01

160

Space Chambers for Crop Treatment  

NASA Technical Reports Server (NTRS)

Vacuum chambers, operated by McDonnell Douglas Corporation to test spacecraft, can also be used to dry water-soaked records. The drying temperature is low enough to allow paper to dry without curling or charging. Agricultural crops may also be dried using a spinoff system called MIVAC, which has proven effective in drying rice, wheat, soybeans, corn, etc. The system is energy efficient and can incorporate a sanitation process for destroying insects without contamination.

1985-01-01

161

The crop growth research chamber  

NASA Technical Reports Server (NTRS)

The Crop Growth Research Chamber (CGRC) has been defined by CELSS principle investigators and science advisory panels as a necessary ground-based tool in the development of a regenerative life support system. The focus of CGRC research will be on the biomass production component of the CELSS system. The ground-based Crop Growth Research Chamber is for the study of plant growth and development under stringently controlled environments isolated from the external environment. The chamber has importance in three areas of CELSS activities: (1) crop research; (2) system control and integration, and (3) flight hardware design and experimentation. The laboratory size of the CGRC will be small enough to allow duplication of the unit, the conducting of controlled experiments, and replication of experiments, but large enough to provide information representative of larger plant communities. Experiments will focus on plant growth in a wide variety of environments and the effects of those environments on plant production of food, water, oxygen, toxins, and microbes. To study these effects in a closed system, tight control of the environment is necessary.

Wagenbach, Kimberly

1993-01-01

162

Outdoor chamber study to test multi-day effects. Volume 2. Environmental chamber data tabulations. Final report, August 1982-August 1984  

SciTech Connect

The smog chamber facilities of the University of California, Riverside were used to collect experimental data to assess the effects of multi-day irradiations on photochemical oxidant formation. This volume contains the printouts of all the data that were collected in the study. These data are suitable for use in developing and testing kinetic mechanisms of photochemical smog formation.

Carter, W.P.L.; Dodd, M.C.; Long, W.D.; Atkinson, R.

1984-12-01

163

Simple Cloud Chambers Using Gel Ice Packs  

ERIC Educational Resources Information Center

Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

Kamata, Masahiro; Kubota, Miki

2012-01-01

164

Mercury Chamber NF-IDS Meeting  

E-print Network

Mercury Chamber Update V. Graves NF-IDS Meeting October 4, 2011 #12;2 Managed by UT-Battelle for the U.S. Department of Energy Mercury Chamber Update Oct 2011 Starting Point: Coil and Shielding Concept IDS120H #12;3 Managed by UT-Battelle for the U.S. Department of Energy Mercury Chamber Update Oct 2011

McDonald, Kirk

165

Wire chamber degradation at the Argonne ZGS  

SciTech Connect

Experience with multiwire proportional chambers at high rates at the Argonne Zero Gradient Synchrotron is described. A buildup of silicon on the sense wires was observed where the beam passed through the chamber. Analysis of the chamber gas indicated that the density of silicon was probably less than 10 ppM.

Haberichter, W.; Spinka, H.

1986-01-01

166

Delay-line readout drift chambers  

NASA Astrophysics Data System (ADS)

Delay-line readout multiwire gas proportional chambers have been constructed that use drift time information to interpolate between anode wires. Position resolutions over the entire active area of the chamber of 150 ?m fwhm are routinely obtained for instantaneous event rates of up to 1 MHz. Chambers with active areas of up to 30 cm by 90 cm have been built.

Atencio, L. G.; Amann, J. F.; Boudrie, R. L.; Morris, C. L.

167

A Sensitive Cloud Chamber without Radioactive Sources  

ERIC Educational Resources Information Center

We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

2012-01-01

168

EPA GAS PHASE CHEMISTRY CHAMBER STUDIES  

EPA Science Inventory

Gas-phase smog chamber experiments are being performed at EPA in order to evaluate a number of current chemical mechanisms for inclusion in EPA regulatory and research models. The smog chambers are 9000 L in volume and constructed of 2-mil teflon film. One of the chambers is co...

169

IFE Chamber Technology Testing Program In NIF and Chamber Development Test Plan Mohamed A. Abdou  

E-print Network

IFE Chamber Technology Testing Program In NIF and Chamber Development Test Plan Mohamed A. Abdou chamber technology testing program in NIF involoving: criteria for evaluation were developed for 2 promising chamber design concepts. Early testing in non-fusionhon-ignition prior

Abdou, Mohamed

170

Hydrocarbon-fuel/combustion-chamber-liner materials compatibility  

NASA Technical Reports Server (NTRS)

Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications.

Gage, Mark L.

1990-01-01

171

THE CIRCUMFUSION SYSTEM FOR MULTIPURPOSE CULTURE CHAMBERS  

PubMed Central

A self-contained mechanical system for circulating nutrient fluid through 12 tissue culture chambers is described in detail. This system utilizes nonperforated cellophane membranes in the chambers which separate the circulating nutrient from the tissue culture environments. The nutrient, therefore, is dialyzed through the cellophane of each chamber; some cell products are retained in the microenvironment between the closely apposed cellophane and cover slip, whereas the other cell products move from chamber to chamber in the circulating nutrient. The resultant environmental conditions directed by the circumfusion systems are highly favorable for maintaining the differentiation of chick embryo tissues over protracted periods; a number of micrographs are shown. PMID:10976203

Rose, George G.

1967-01-01

172

Portable Ethylene Oxide Sterilization Chamber  

PubMed Central

A portable ethylene oxide sterilization chamber was designed, constructed, and tested for use in the sterilization of embolectomy catheters. The unit can accommodate catheters up to 40 inches (101.6 cm) in length and can be operated for less than 4 cents per cycle. A constant concentration of 500 mg of ethylene oxide per liter of space and holding periods of 4 and 6 hr at 43 and 22 C, respectively, were adequate when tested with B. subtilis spores. The estimated cost of construction was $165.00. If temperature control is unnecessary, the cost is approximately $80.00. Images PMID:4977644

Songer, J. R.; Mathis, R. G.

1969-01-01

173

Plasma Opening Switch Synchronization Facility  

NASA Astrophysics Data System (ADS)

The Baikal program provides a superpower generator creation which uses a plasma opening switch for output pulse production. The MOL facility is being developed within the frames of this program to test main units and systems of the planned generator at 4-6 MV, 3 MA and 100 ns. The MOL facility is planned to use 7 parallel plasma opening switch modules placed in the relatively compact vacuum chamber of 140 cm diameter. This aims at solving two main technical issued: plasma opening switch module development with external applied magnetic field and plasma switch modules synchronization. The paper describes plasma switch module design and low inductance load synchronization experimental tests results.

Altuhov, Aleksey A.; Blinov, Petr I.; Dolgachev, Georgi I.; Maslennikov, Dmitry D.; Khodeev, Ivan A.

2002-12-01

174

Formation of crustal magma chambers in Iceland  

SciTech Connect

Formation of crustal magma chambers in Iceland may be facilitated by the occurrence of stress barriers that lead to formation of thick sills. Such sills absorb the magma of all dikes that enter them and may evolve into magma chambers. Ideal sites for stress barriers, and hence for magma chambers, are rock formations where individual layers have different elastic properties. The rocks formed during the Pleistocene have notably different elastic properties, and when buried in the volcanic zones, they form more promising sites for magma chambers than the Tertiary rocks. This may explain why the number of magma chambers, indicated by the number of corresponding central volcanoes, during the late Pleistocene (i.e., during the past 0.7 m.y.) appears to be proportionally greater than the number of chambers (i.e., central volcanoes) active during Tertiary time.

Gudmundsson, A.

1986-02-01

175

FULL-SCALE CHAMBER INVESTIGATION AND SIMULATION OF AIR FRESHENER EMISSIONS IN THE PRESENCE OF OZONE  

EPA Science Inventory

The paper discusses results of tests, conducted in the EPA large chamber facility, determining emissions and chemical degradation of volatile organic compounds (VOCs) from one electrical plug-in type pine-scented air freshener in the presence of ozone supplied by a device markete...

176

EVALUATION OF THE FLUX CHAMBER METHOD FOR MEASURING VOLATILE ORGANIC EMISSIONS FROM SURFACE IMPOUNDMENTS  

EPA Science Inventory

This research deals with the validation of the flux chamber method for measuring volatile organic emissions from liquid surfaces in treatment, storage and disposal facilities (TSDF). A simulated surface impoundment was constructed so that method precision and accuracy could be de...

177

MECHANISMS OF PHOTOCHEMICAL REACTIONS IN URBAN AIR. VOLUME II. CHAMBER STUDIES  

EPA Science Inventory

The smog chamber facility of the Statewide Air Pollution Research Center has been employed in a study designed to provide experimental data required for the validation of kinetic computer models of chemical transformations in polluted atmospheres. A 5800-l, Teflon-coated, evacuab...

178

INHALATION TOXICOLOGY OF RED AND VIOLET MIXTURES - CHAMBER CONCENTRATION AND PARTICLE SIZE DISTRIBUTION REPORT  

EPA Science Inventory

An inhalation exposure facility was developed at the U.S. EPA, RTP, NC to conduct inhalation exposures of rodents and guinea pigs to dye mixtures used by the U.S. Army in the manufacture of smoke munitions. nitially, an evaluation of the prototype chamber aerosol homogeneity was ...

179

PSL Icing Facility Upgrade Overview  

NASA Technical Reports Server (NTRS)

The NASA Glenn Research Center Propulsion Systems Lab (PSL) was recently upgraded to perform engine inlet ice crystal testing in an altitude environment. The system installed 10 spray bars in the inlet plenum for ice crystal generation using 222 spray nozzles. As an altitude test chamber, the PSL is capable of simulating icing events at altitude in a groundtest facility. The system was designed to operate at altitudes from 4,000 to 40,000 ft at Mach numbers up to 0.8M and inlet total temperatures from -60 to +15 degF. This paper and presentation will be part of a series of presentations on PSL Icing and will cover the development of the icing capability through design, developmental testing, installation, initial calibration, and validation engine testing. Information will be presented on the design criteria and process, spray bar developmental testing at Cox and Co., system capabilities, and initial calibration and engine validation test. The PSL icing system was designed to provide NASA and the icing community with a facility that could be used for research studies of engine icing by duplicating in-flight events in a controlled ground-test facility. With the system and the altitude chamber we can produce flight conditions and cloud environments to simulate those encountered in flight. The icing system can be controlled to set various cloud uniformities, droplet median volumetric diameter (MVD), and icing water content (IWC) through a wide variety of conditions. The PSL chamber can set altitudes, Mach numbers, and temperatures of interest to the icing community and also has the instrumentation capability of measuring engine performance during icing testing. PSL last year completed the calibration and initial engine validation of the facility utilizing a Honeywell ALF502-R5 engine and has duplicated in-flight roll back conditions experienced during flight testing. This paper will summarize the modifications and buildup of the facility to accomplish these tests.

Griffin, Thomas A.; Dicki, Dennis J.; Lizanich, Paul J.

2014-01-01

180

Fluidized wall for protecting fusion chamber walls  

DOEpatents

Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

Maniscalco, James A. (Danville, CA); Meier, Wayne R. (Livermore, CA)

1982-01-01

181

Drift chamber tracking with neural networks  

SciTech Connect

We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

Lindsey, C.S.; Denby, B.; Haggerty, H.

1992-10-01

182

Free-Flow Open-Chamber Electrophoresis  

NASA Technical Reports Server (NTRS)

Free-flow open-chamber electrophoresis variant of free-flow electrophoresis performed in chamber with open ends and in which velocity of electro-osmotic flow adjusted equal to and opposite mean electrophoretic velocity of sample. Particles having electrophoretic mobilities greater than mean mobility of sample particles move toward cathode, those with mobilities less move toward anode. Technique applied to separation of components of mixtures of biologically important substances. Sensitivity enhanced by use of tapered chamber.

Sharnez, Rizwan; Sammons, David W.

1994-01-01

183

The NASA Ames Controlled Environment Research Chamber: Present status  

NASA Technical Reports Server (NTRS)

The Controlled Environment Research Chamber (CERC) at the NASA Ames Research Center was created for early-on investigation of promising new technologies for life support of advanced space exploration missions. The CERC facility is being used to address the advanced technology requirements necessary to implement an integrated working and living environment for a planetary habitat. The CERC, along with a human-powered centrifuge, a planetary terrain simulator, advanced displays, and a virtual reality, is able to develop and demonstrate applicable technologies for future planetary exploration. There will be several robotic mechanisms performing exploration tasks external to the habitat that will be controlled through the virtual environment to provide representative workloads for the crew. Finally, there will be a discussion of innovative new multidisciplinary test facilities, and how effective they are to the investigation of the wide range of human and machine problems inherent in exploration missions.

Gross, Anthony R.; Korsmeyer, David J.; Harper, Lynn D.; Force, Edwin L.

1994-01-01

184

The NASA Ames Controlled Environment Research Chamber - Present status  

NASA Technical Reports Server (NTRS)

The Controlled Environment Research Chamber (CERC) at the NASA Ames Research Center was created for early-on investigation of promising new technologies for life support of advanced space exploration missions. The CERC facility is being used to address the advanced technology requirements necessary to implement an integrated working and living environment for a planetary habitat. The CERC, along with a human-powered centrifuge, a planetary terrain simulator, advanced displays, and a virtual reality capability, is able to develop and demonstrate applicable technologies for future planetary exploration. There will be several robotic mechanisms performing exploration taskes external to the habitat that will be controlled through the virtual environment to provide representative workloads for the crew. Finally, there will be a discussion of innovative new multidisciplinary test facilities, and how effective they are to the investigation of the wide range of human and machine problems inherent in exploration missions.

Gross, Anthony R.; Korsmeyer, David J.; Harper, Lynn D.; Force, Edwin L.

1994-01-01

185

Compressive sensing beamforming based on covariance for acoustic imaging with noisy  

E-print Network

, on the other hand, uses a different array layout. Aeroacoustic experiments performed in wind tunnel and anechoic chamber jet facility usually contain strong background noise at broad- band frequencies in the frequency domain. For a single signal of interest Sðjx� 2 C1 in a free propagation space, using

Huang, Xun

186

The Mark II Vertex Drift Chamber  

SciTech Connect

We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 {mu}m spatial resolution and <1000 {mu}m track-pair resolution in pressurized CO{sub 2} gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO{sub 2} mixtures are presented. 10 refs., 12 figs., 1 tab.

Alexander, J.P.; Baggs, R.; Fujino, D.; Hayes, K.; Hoard, C.; Hower, N.; Hutchinson, D.; Jaros, J.A.; Koetke, D.; Kowalski, L.A.

1989-03-01

187

LAYOUT AND SIZING OF ESF ALCOVES AND REFUGE CHAMBERS  

SciTech Connect

The purpose of this analysis is to establish size requirements and approximate locations of Exploratory Studies Facility (ESF) test and operations alcoves, including refuge chambers during construction of the Topopah Spring (TS) loop. Preliminary conceptual layouts for non-deferred test alcoves will be developed to examine construction feasibility based on current test plans and available equipment. The final location and configuration layout for alcoves will be developed when in-situ rock conditions can be visually determined. This will be after the TBM has excavated beyond the alcove location and the rock has been exposed. The analysis will examine the need for construction of walkways and electrical alcoves in the ramps and main drift. Niches that may be required to accommodate conveyor booster drives and alignments are not included in this analysis. The analysis will develop design criteria for refuge chambers to meet MSHA requirements and will examine the strategic location of refuge chambers based on their potential use in various ESF fire scenarios. This document supersedes DI:BABE00000-01717-0200-00003 Rev 01, ''TS North Ramp Alcove and Stubout Location Analysis'' in its entirety (Reference 5-6).

John Beesley and Romeo S. Jurani

1995-08-25

188

Modeling smog chamber measurements of vehicle exhaust VOC reactivities  

SciTech Connect

Vehicle exhaust VOC reactivities, measured at GM`s smog chamber facility, have been modeled using the SAPRC93 photochemical mechanism. The vehicle exhaust mixtures were generated by a single vehicle run over a portion of the Federal Test Procedure using three Auto/Oil reformulated test gasolines. For each run, up to 156 individual VOC species were identified. Initial HONO concentrations are needed to simulate reactivity measurement runs. (HONO is expected to be generated in a Tedlar bag holding the exhaust sample prior to its transfer to the smog chambers.) Measured and simulated relative incremental reactivities for the three exhaust mixtures are highly consistent. However, measured relative incremental reactivities are more sensitive to fuel effects than simulated ones. The maximum incremental reactivity (MIR)-based relative incremental reactivities, derived from individual species concentrations and MIR factors, are very close to simulated ones. A number of sensitivity simulation runs have been carried out to investigate the impact of HONO and other variables. Results show that relative reactivities of actual vehicle exhaust emissions can be measured by chamber runs in spite of the HONO effect.

Chang, T.Y.; Nance, B.I. [Ford Motor Co., Dearborn, MI (United States). Ford Research Lab.; Kelly, N.A. [General Motors R and D Center, Warren, MI (United States)

1997-12-31

189

study on trace contaminants control assembly for sealed environment chamber  

NASA Astrophysics Data System (ADS)

The biological and Physicochemical P C life support technologies are all important parts to establish a human Closed Ecological Life Support System CELSS for long-duration mission The latter has the advantages of lower power consumption lower mass and higher efficiency therefore researchers often incorporate the use of biological systems with P C life support technologies to continuously recycle air water and part of the solid waste stream generated such as the Russian BLSS and the NASA-sponsored Lunar-Mars Life Support Test Project LMLSTP In short these tests were very successful in integrating biological and P C life support technologies for long-duration life support Therefore we should use a combination of integrated biological with P C life support technologies in a human CELSS Human construction materials plants animals and soils release much trace toxic gases in a CELSS and they will inhibit plant growth and badly affect human health when their concentrations rise over their threshold levels The effect of biological trace contaminant control technologies is slower especially for a human sealed chamber because human produce much more methane and other contaminants A regenerative Trace Contaminant Control Subsystem TCCS with P C technology is a more important part in this case to control quickly the airborne contaminants levels and assure human in good condition in a sealed chamber This paper describes a trace contaminant control test facility incorporated a 8 m3 sealed environment chamber a regenerative TCCS with P C

Pang, L. P.; Wang, J.; Liu, L. K.; Liu, H.

190

The JPL Molecular Contamination Investigation Facility  

NASA Technical Reports Server (NTRS)

The Molecular Contamination Investigation Facility (MCIF) is discussed in terms of its use for improving the far-UV performance of a camera and its broader applications. The MCIF incorporates two independent vacuum systems with sample isolation chambers and regulated heat exchangers as well as three quartz-crystal microbalances (QCMs) and a residual gas analyzer. One cryogenic QCM is heat sunk into an LN2 heat exchanger, while the others are thermoelectrically controlled and are heat sunk into a regulated heat exchanger. Outgas accumulation can be measured at three surface temperatures between -180 and 80 C simultaneously, and results are presented for the testing of 34 samples in a large-chambered system and 22 samples in a system with a smaller chamber. The MCIF results provide a database for fabrication processes, material selection, maximum bakeout temperatures, and the development of an ultraclean bakeout chamber.

Taylor, Daniel M.; Soules, David; Osborn, David

1990-01-01

191

Automated Transmission Loss Measurement in the Structural Acoustic Loads and Transmission Facility at NASA Langley Research Center  

NASA Technical Reports Server (NTRS)

A technique to measure the radiated acoustic intensity and transmission loss of panels is documented in this paper. This facility has been upgraded to include a test fixture that scans the acoustic intensity radiated from a panel on the anechoic receiving room side of the transmission loss window. The acoustic intensity incident on the panel from the reverberant side of the transmission loss window is estimated from measurements made using six stationary microphones in the reverberant source room. From the measured incident and radiated intensity, the sound power transmission loss is calculated. The setup of the facility and data acquisition system are documented. A transmission loss estimate of a typical panel is shown. The measurement-to-measurement and setup-to-setup repeatability of the transmission loss estimate are assessed. Conclusions are drawn about the ability to measure changes in transmission loss due to changes in panel construction.

Klos, J.; Brown, S. A.

2002-01-01

192

LABORATORY ANIMAL FACILITIES STANDARD OPERATING PROCEDURE  

E-print Network

Faculty, students, and technicians who work with live animals in their labs or testing rooms. 2.0 Procedure 2.1 All equipment, transfer boxes, and holding/testing chambers used for animal research1.C.7 LABORATORY ANIMAL FACILITIES STANDARD OPERATING PROCEDURE FOR SANITATION OF RESEARCH

Krovi, Venkat

193

Intercalibration of benthic flux chambers I. Accuracy of flux measurements and influence of chamber hydrodynamics  

Microsoft Academic Search

The hydrodynamic properties and the capability to measure sediment–water solute fluxes, at assumed steady state conditions, were compared for three radically different benthic chamber designs: the “Microcosm”, the “Mississippi” and the “Göteborg” chambers. The hydrodynamic properties were characterized by mounting a PVC bottom in each chamber and measuring mixing time, diffusive boundary layer thickness (DBL thickness) shear velocity (u?), and

A. Tengberg; H. Stahl; G. Gust; V. Müller; U. Arning; H. Andersson; P. O. J. Hall

2004-01-01

194

Using a ceramic chamber in kicker magnets  

Microsoft Academic Search

A ceramic chamber inside kicker magnets can provide the relevant field risetime. On the other hand, some metallic coating inside has to prevent static charge buildup and shield the beam from ceramic and ferrite at high frequencies to avoid possible resonances. The issues concerning the metallized ceramic chamber, such as coupling impedances and requirements on the coating, are studied to

S. S. Kurennoy

1993-01-01

195

Results from the MAC Vertex chamber  

SciTech Connect

The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 ..mu..m in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed.

Nelson, H.N.

1987-05-01

196

Performance of the continuous flow diffusion chambers  

NASA Technical Reports Server (NTRS)

A brief comparative description is made of the chambers. Overall, comparisons for the various types of experiments - monodisperse, polydisperse and ambient aerosol - showed agreement among these chambers to within 15% in most cases. A careful analysis of the results indicated that a proper accounting of certain parameters would bring about much closer agreement among four of these instruments.

Hudson, J. G.; Alofs, D. J.

1982-01-01

197

The Meditation Chamber: Towards Self-Modulation  

E-print Network

The Meditation Chamber: Towards Self-Modulation Chris Shaw Simon Fraser University, Canada Diane The Meditation Chamber is an immersive virtual environment (VE), initially created to enhance and augment the existing methods of training users how to meditate, and by extension, to realize the benefits from

Shaw, Chris

198

Influence of high rotational speeds on heat transfer and oil film thickness in aero-engine bearing chambers  

Microsoft Academic Search

Increasing the thermal loading of bearing chambers in modern aero-engines requires advanced techniques for the determination of heat transfer characteristics. In the present study, film thickness and heat transfer measurements have been carried out for the complex two-phase oil\\/air flow in bearing chambers. In order to ensure real engine conditions, a new test facility has been built up, designed for

S. Wittig; A. Glahn; J. Himmelsbach

1994-01-01

199

Advanced tube-bundle rocket thrust chamber  

NASA Technical Reports Server (NTRS)

An advanced rocket thrust chamber for future space application is described along with an improved method of fabrication. Potential benefits of the concept are improved cyclic life, reusability, and performance. Performance improvements are anticipated because of the enhanced heat transfer into the coolant which will enable higher chamber pressure in expander cycle engines. Cyclic life, reusability and reliability improvements are anticipated because of the enhanced structural compliance inherent in the construction. The method of construction involves the forming of the combustion chamber with a tube-bundle of high conductivity copper or copper alloy tubes, and the bonding of these tubes by an electroforming operation. Further, the method of fabrication reduces chamber complexity by incorporating manifolds, jackets, and structural stiffeners while having the potential for thrust chamber cost and weight reduction.

Kazaroff, John M.; Pavli, Albert J.

1990-01-01

200

RCRA FACILITIES  

EPA Science Inventory

Points represent facilities that are regulated by the EPA under the Resource Conservation and Recovery Act (RCRA). Facilities regulated under RCRA generate, dispose of, treate or transport hazardous waste. RCRA is a law enacted by Congress in 1976 and amended in 1984 to include ...

201

Nuclear Facilities  

NSDL National Science Digital Library

In order to produce nuclear weapons, each country must have facilities to produce and refine the nuclear materials, conduct research on weapon design, and store the completed weapons. The interactives in this collection allow you to explore the nuclear facilities of the nuclear powers (both declared and undeclared).

Christopher Griffith

202

A new gun facility dedicated to performing shock physics and terminal ballistics experiments  

NASA Astrophysics Data System (ADS)

A new building has been constructed to house various powder and single-stage and two-stage gas guns at the Naval Surface Warfare Center, Indian Head Division. Guns previously located at the Naval Research Laboratory and the former White Oak Site of the Naval Surface Warfare Center have been relocated here. Most of the guns are mounted on moveable pedestals to allow them to be shot into various chambers. The facility includes a concrete blast chamber, a target chamber/catch tank for flyer plate experiments, and a target chamber outfitted for terminal ballistics measurements. This paper will discuss the capabilities of this new facility.

Zakraysek, Alan J.; Sutherland, Gerrit T.; Sandusky, Harold D.; Strange, David

2000-04-01

203

The NASA Ames Closed Environmental Research Chamber: Present Status  

NASA Technical Reports Server (NTRS)

The Closed Environmental Research Chamber (CERC) at the NASA Ames Research Center was created to investigate both components and complete systems for life support of advanced space exploration missions. This facility includes a Main Chamber, an Airlock, a Sample Transfer Lock, a Vacuum System, an Air Recompression System, a dedicated control room and a pit area for housing supporting and environmental control systems. The Main Chamber provides 310 sq ft of internal working/living space on two levels. It is planned that the CERC will be a human-rated facility for habitation simulation under mass balance closure conditions. The internal pressure will be variable over the range of 14.7 psia to 5 psia with accompanying capability for variation in atmosphere composition to maintain the oxygen partial pressure at 160 mm Hg. The CERC will be provided with a core set of primary life support subsystems for temperature and humidity control, C02 removal and trace contaminant control. Interfacing with external life support technology test bds with be provided, along with connection to centralized, microprocessor-based data acquisition and control systems. This paper will discuss the current status of the CERC facility and show how it is being used to address the advanced technology requirements necessary to implement an integrated working and living environment for a planetary habitat. In particular, it will be shown how the CERC, along with a human-powered centrifuge, a planetary terrain simulator and advanced displays and a virtual reality capability will work together to develop and demonstration applicable technologies for future planetary habitats. Artificial intelligence and expert system programming techniques will be used extensively to provide an automated environment for a 4-person crew. There will be several robotic mechanisms performing exploration tasks external to the habitat that will be controlled through the virtual environment to provide representative workloads for the crew. Finally, there will be a discussion of how effective are innovative new multidisciplinary test facilities to the investigation of the wide range of human and machine problems inherent in exploration missions.

Gross, Anthony R.; Korsmeyer, David J.; Harper, Lynn D.; Force, Edwin L.

1994-01-01

204

Periphyton metabolism: A chamber approach  

NASA Astrophysics Data System (ADS)

In lotic ecosystems, the metabolism of periphyton is influenced strongly by natural and anthropogenic disturbances such as floods. Using recirculating metabolism chambers, we measured the metabolic activity of the Cladophora glomerata-dominated periphyton community in the Glen Canyon Dam tailwater, in relation to the 1996 controlled flood. Because scouring removes senescent plant material and detritus from periphyton, we hypothesized that productivity rates and the gross productivity/respiration (P/R) ratio of the periphyton community would be greater after the flood. Gross and net primary production (as chlorophyll-a) increased significantly after the flood and an approximately 2-fold increase was observed in net daily metabolism. Mean P/R ratio increased significantly from 1.3 in the pre-flood community to 2.6 in the post-flood community. Following the flood, periphyton on the rocks exhibited increased photosynthetic efficiency relative to measurements made before the flood. Given the importance of primary producers in desert rivers, such changes have implications for ecologically sound management of the Colorado and other rivers.

Brock, James T.; Royer, Todd V.; Snyder, Eric B.; Thomas, Steven A.

205

Temperature dependent BRDF facility  

NASA Astrophysics Data System (ADS)

Applications involving space based instrumentation and aerodynamically heated surfaces often require knowledge of the bi-directional reflectance distribution function (BRDF) of an exposed surface at high temperature. Addressing this need, the Johns Hopkins University Applied Physics Laboratory (JHU/APL) developed a BRDF facility that features a multiple-port vacuum chamber, multiple laser sources covering the spectral range from the longwave infrared to the ultraviolet, imaging pyrometry and laser heated samples. Laser heating eliminates stray light that would otherwise be seen from a furnace and requires minimal sample support structure, allowing low thermal conduction loss to be obtained, which is especially important at high temperatures. The goal is to measure the BRDF of ceramic-coated surfaces at temperatures in excess of 1000°C in a low background environment. Most ceramic samples are near blackbody in the longwave infrared, thus pyrometry using a LWIR camera can be very effective and accurate.

Airola, Marc B.; Brown, Andrea M.; Hahn, Daniel V.; Thomas, Michael E.; Congdon, Elizabeth A.; Mehoke, Douglas S.

2014-09-01

206

A Dedicated Facility to Perform Powder and Light Gas Gun Experiments  

NASA Astrophysics Data System (ADS)

A new building has been constructed to house various powder, single and two-stage gas guns at the Naval Surface Warfare Center, Indian Head. Guns previously located at the Naval Research Laboratory and the former White Oak Site of the Naval Surface Warfare Center have been relocated. Most of the guns are mounted on movable pedestals to allow them to be shot into various chambers. These chambers are a concrete blast chamber, a target chamber/catch tank for flyer plate experiments, and a target chamber outfitted for terminal ballistics measurements. This paper will discuss the capabilities of this new facility.

Zakraysek, A. J.; Sutherland, G. T.; Sandusky, H. D.

1999-06-01

207

Outdoor chamber study to test multi-day effects. Volume 3. Documentation for computer-readable environmental chamber data. Final report, August 1982-August 1984  

SciTech Connect

The smog chamber facilities of the University of California, Riverside were used to collect experimental data to assess the effects of multi-day irradiations on photochemical oxidant formation. This volume includes documentation on the computer-readable magnetic tape that contains all the data collected in the study. The tape is suitable for use by modelers to develop and test kinetic mechanisms of photochemical smog formation.

Carter, W.P.L.; Dodd, M.C.; Long, W.D.; Atkinson, R.

1984-12-01

208

BOREAS TGB-3 CH4 and CO2 Chamber Flux Data over NSA Upland Sites  

NASA Technical Reports Server (NTRS)

The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-3) team collected methane and carbon dioxide (CH4, CO2) chamber flux measurements at the Northern Study Area (NSA) Fen, Old Black Spruce (OBS), Young Jack Pine (YJP), and auxiliary sites along Gillam Road and the 1989 burn site. Gas samples were extracted from chambers and analyzed at the NSA lab facility approximately every 7 days during May to September 1994 and June to October 1996. The data are provided in tabular ASCII files.

Savage, Kathleen; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Moore, Tim R.

2000-01-01

209

IFE thick liquid wall chamber dynamics: Governing mechanisms andmodeling and experimental capabilities  

SciTech Connect

For thick liquid wall concepts, it is important to understand the different mechanisms affecting the chamber dynamics and the state of the chamber prior to each shot a compared with requirements from the driver and target. These include ablation mechanisms, vapor transport and control, possible aerosol formation, as well as protective jet behavior. This paper was motivated by a town meeting on this subject which helped identify the major issues, assess the latest results, review the capabilities of existing modeling and experimental facilities with respect to addressing remaining issues, and helping guide future analysis and R&D efforts; the paper covers these exact points.

Raffray, A.R.; Meier, W.; Abdel-Khalik, S.; Bonazza, R.; Calderoni, P.; Debonnel, C.S.; Dragojlovic, Z.; El-Guebaly, L.; Haynes,D.; Latkowski, J.; Olson, C.; Peterson, P.F.; Reyes, S.; Sharpe, P.; Tillack, M.S.; Zaghloul, M.

2005-01-24

210

Construction of a fast ionization chamber for high-rate particle identification  

NASA Astrophysics Data System (ADS)

A new gas-filled ionization chamber for high count rate particle identification has been constructed and commissioned at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). To enhance the response time of the ionization chamber, a design utilizing a tilted entrance window and tilted electrodes was adopted, which is modified from an original design by Kimura et al. [1]. A maximum counting rate of ~700,000 particles per second has been achieved. The detector has been used for several radioactive beam measurements performed at the HRIBF.

Chae, K. Y.; Ahn, S.; Bardayan, D. W.; Chipps, K. A.; Manning, B.; Pain, S. D.; Peters, W. A.; Schmitt, K. T.; Smith, M. S.; Strauss, S. Y.

2014-07-01

211

The emulsion chamber technology experiment  

NASA Technical Reports Server (NTRS)

Photographic emulsion has the unique property of recording tracks of ionizing particles with a spatial precision of 1 micron, while also being capable of deployment over detector areas of square meters or 10's of square meters. Detectors are passive, their cost to fly in Space is a fraction of that of instruments of similar collecting. A major problem in their continued use has been the labor intensiveness of data retrieval by traditional microscope methods. Two factors changing the acceptability of emulsion technology in space are the astronomical costs of flying large electronic instruments such as ionization calorimeters in Space, and the power and low cost of computers, a small revolution in the laboratory microscope data-taking. Our group at UAH made measurements of the high energy composition and spectra of cosmic rays. The Marshall group has also specialized in space radiation dosimetry. Ionization calorimeters, using alternating layers of lead and photographic emulsion, to measure particle energies up to 10(exp 15) eV were developed. Ten balloon flights were performed with them. No such calorimeters have ever flown in orbit. In the ECT program, a small emulsion chamber was developed and will be flown on the Shuttle mission OAST-2 to resolve the principal technological questions concerning space exposures. These include assessments of: (1) pre-flight and orbital exposure to background radiation, including both self-shielding and secondary particle generation; the practical limit to exposure time in space can then be determined; (2) dynamics of stack to optimize design for launch and weightlessness; and (3) thermal and vacuum constraints on emulsion performance. All these effects are cumulative and affect our ability to perform scientific measurements but cannot be adequately predicted by available methods.

Gregory, John C.

1992-01-01

212

Vapor wall deposition in Teflon chambers  

NASA Astrophysics Data System (ADS)

Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, ?-pinene, and dodecane in two chambers that had been extensively used and in two new unused chambers. We found that the extent of prior use of the chamber did not significantly affect the sorption behavior of the Teflon films. The dominant parameter governing the extent of wall deposition of a compound is its wall accommodation coefficient (?w,i), which can be correlated through its volatility (Ci*) with the number of carbons (nC) and oxygens (nO) in the molecule. Among the 25 compounds studied, the maximum wall deposition rate is approached by the most highly oxygenated and least volatile compounds. The extent to which vapor wall deposition impacts measured SOA yields depends on the competition between uptake of organic vapors by suspended particles and chamber walls. Gas-particle equilibrium partitioning is established relatively rapidly in the presence of perfect accommodation of organic vapors onto particles or when a sufficiently large concentration of suspended particles is present. The timescale associated with vapor wall deposition can vary from minutes to hours depending on the value of ?w,i. For volatile and intermediate volatility organic compounds (small ?w,i), gas-particle partitioning will be dominant for typical particle number concentrations in chamber experiments. For large ?w,i, vapor transport to particles is suppressed by competition with the chamber walls even with perfect particle accommodation.

Zhang, X.; Schwantes, R. H.; McVay, R. C.; Lignell, H.; Coggon, M. M.; Flagan, R. C.; Seinfeld, J. H.

2014-10-01

213

The Japanese Radon and Thoron Reference Chambers  

SciTech Connect

Passive detectors used for large-scale and long-term surveys are generally calibrated in a well-controlled environment such as a radon chamber. It has been also pointed out that some of them are sensitive to thoron. Thus it is necessary to check the thoron contribution to the detector response with the proposed or similar test before practical use. The NIRS accommodates radon/aerosol and thoron chambers for quality assurance and quality control of radon measurements. Thus both chambers work so well that they can supply us with the calibration technique and consequently, a good level of knowledge of the radon and thoron issue.

Tokonami, Shinji; Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Takahashi, Hiroyuki; Miyahara, Nobuyuki [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

2008-08-07

214

Aerosol Production in IFE Chamber Systems  

SciTech Connect

Preliminary studies have been performed to evaluate the production of aerosols in wetted wall and solid wall IFE chamber configurations. Molten lead and flibe were examined for a wetted-wall chamber 6.5 m in radius, giving aerosol mass concentrations of 20 mg/m{sup 3} and 10 mg/m{sup 3}, respectively, for a simulated 458 MJ indirect-drive target microexplosion. Solid wall materials of tungsten and steel exposed to a 154 MJ direct-drive target microexplosion within an equivalent chamber produced mass concentrations of 0.4 mg/m{sup 3} and 90 mg/m{sup 3}, respectively.

Sharpe, J.P.; Merrill, B.J.; Petti, D.A. [Idaho National Engineering and Environmental Laboratory (United States)

2003-09-15

215

Development of a EUV Test Facility at the Marshall Space Flight Center  

NASA Technical Reports Server (NTRS)

This paper will describe a new EUV test facility that is being developed at the Marshall Space Flight Center (MSFC) to test EUV telescopes. Two flight programs, HiC - high resolution coronal imager (sounding rocket) and SUVI - Solar Ultraviolet Imager (GOES-R), set the requirements for this new facility. This paper will discuss those requirements, the EUV source characteristics, the wavelength resolution that is expected and the vacuum chambers (Stray Light Facility, Xray Calibration Facility and the EUV test chamber) where this facility will be used.

West, Edward; Pavelitz, Steve; Kobayashi, Ken; Robinson, Brian; Cirtain, Johnathan; Gaskin, Jessica; Winebarger, Amy

2011-01-01

216

Development of a EUV test facility at the Marshall Space Flight Center  

NASA Astrophysics Data System (ADS)

This paper will describe a new Extreme Ultraviolet (EUV) test facility that is being developed at the Marshall Space Flight Center (MSFC) to test EUV telescopes. Two flight programs, Hi-C, the high resolution coronal imager (a sounding rocket program), and SUVI, the Solar Ultraviolet Imager (GOES-R), set the requirements for this new facility. This paper will discuss those requirements, the EUV source characteristics, the wavelength resolution that is expected and the vacuum chambers (Stray Light Facility, Xray Calibration Facility and the NSSTC EUV test chamber) where this facility will be used.

West, Edward; Pavelitz, Steve; Kobayashi, Ken; Robinson, Brian; Cirtain, Jonathan; Gaskin, Jessica; Winebarger, Amy; Krause, Linda; McGuirk, Michael; Darnel, Jonathan

2011-09-01

217

21 CFR 884.5225 - Abdominal decompression chamber.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Abdominal decompression chamber. 884.5225 Section...Devices § 884.5225 Abdominal decompression chamber. (a) Identification. An abdominal decompression chamber is a hoodlike device...

2010-04-01

218

21 CFR 874.1060 - Acoustic chamber for audiometric testing.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Acoustic chamber for audiometric testing...Diagnostic Devices § 874.1060 Acoustic chamber for audiometric testing...a) Identification. An acoustic chamber for audiometric testing is a room that is intended for...

2010-04-01

219

FACILITY DATABASE  

Cancer.gov

January 2008 LASP FACILTY Database Form 5.000 Issue Reporting Form This form is used to report data and/or program related issues regarding the FACILITY database, Supplemental, or the LASP Online Access System. Before submitting this form,

220

Health Facilities  

MedlinePLUS

Health facilities are places that provide health care. They include hospitals, clinics, outpatient care centers, and specialized care centers, such as birthing centers and psychiatric care centers. When you choose ...

221

Facility Planning.  

ERIC Educational Resources Information Center

This article reviews recommendations on policies for leasing surplus school space made during the Council of Educational Facility Planners/International conference. A case study presentation of a Seattle district's use of lease agreements is summarized. (MJL)

Graves, Ben E.

1984-01-01

222

Characterization and testing of a new environmental chamber designed for emission aging studies  

NASA Astrophysics Data System (ADS)

A 29 m3 Teflon chamber, designed for aging studies of combustion aerosols, at the University of Eastern Finland is described and characterized. The chamber belongs to a research facility, called Ilmari, where small-scale combustion devices, a dynamometer for vehicle exhaust studies, dilution systems, the chamber, as well as cell and animal exposure devices are side by side under the same roof. The small surface-to-volume ratio of the chamber enables reasonably long experiment times, with particle wall loss rate constants of 0.088, 0.080, 0.045, and 0.040 h-1 for polydisperse, 50, 100, and 200 nm monodisperse aerosols, respectively. The NO2 photolysis rate can be adjusted from zero to 0.62 min-1. The irradiance spectrum is centered at 365 nm and the maximum irradiance, produced by 160 blacklight lamps, is 29.7 W m-2, which corresponds to the UV irradiance in Central Finland at noon on a sunny day in the midsummer. The temperature inside the chamber is uniform and can be kept at 25 ± 1 °C when half of the blacklights are on. The chamber is kept in an overpressure with a moving top frame, which prevents sample dilution and contamination from entering the chamber during an experiment. The functionality of the chamber was tested with oxidation experiments of toluene, resulting in secondary organic aerosol (SOA) yields of 33-44%, depending on the initial conditions, such as the NOx concentration. The highest gaseous oxidation product yields of 14.4-19.5% were detected with ions corresponding to 2-butenedial (m/z 73.029) and 4-oxo-2-pentenal (m/z 99.044). Overall, reasonable yields of SOA and gaseous reaction products, comparable to those obtained in other laboratories, were obtained.

Leskinen, A.; Yli-Pirilä, P.; Kuuspalo, K.; Sippula, O.; Jalava, P.; Hirvonen, M.-R.; Jokiniemi, J.; Virtanen, A.; Komppula, M.; Lehtinen, K. E. J.

2014-06-01

223

21 CFR 866.2120 - Anaerobic chamber.  

Code of Federal Regulations, 2013 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An...

2013-04-01

224

21 CFR 866.2120 - Anaerobic chamber.  

Code of Federal Regulations, 2011 CFR

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An...

2011-04-01

225

21 CFR 866.2120 - Anaerobic chamber.  

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An...

2014-04-01

226

Calibration of the ATLAS Muon Chambers  

NASA Astrophysics Data System (ADS)

The high-pressure drift tube chambers for the muon spectrometer of the ATLAS detector at the LHC have to provide a track position resolution of 40 ?m. The chambers consist of two triple or quadruple layers of drift tubes of 30 mm diameter with a average spatial resolution of 80 ?m. The precise knowledge of the space-to-drift-time relation r(t) to better than 20 ?m is mandatory. It has to be recalibrated every few hours during ATLAS data taking using muon tracks from a dedicated data stream. The data of the stream will be processed at three calibration centres such that a new drift chamber calibration will be provided within a few hours after data taking. We shall present the drift-chamber calibration concepts, the key features of the calibration algorithms, and the results of the calibration of cosmic muon data recorded by the ATLAS detector.

Rauscher, Felix

2010-04-01

227

The Mars Chamber - Duration: 1:51.  

NASA Video Gallery

The Mars chamber is a box about the size of a refrigerator that re-creates the temperatures, pressures, and atmosphere of the Martian surface, essentially creating a Mars environment on Earth! Scie...

228

Tracks in a hydrogen bubble chamber  

NSDL National Science Digital Library

This Particle Physics UK Image of the Month shows particle tracks in a liquid hydrogen-filled bubble chamber. The page contains a paragraph that explains the most distinctive tracks. A high resolution image is provided.

2007-07-26

229

EFFECT OF DIETHYLHYDROXYLAMINE ON SMOG CHAMBER IRRADIATIONS  

EPA Science Inventory

The addition of diethylhydroxylamine (DEHA) to the urban atmosphere had been suggested as a means of preventing photochemical smog. Smog chamber studies were carried out to investigate the photochemical smog formation characteristics of irradiated hydrocarbon-nitrogen oxides - DE...

230

Formation mechanisms of combustion chamber deposits  

E-print Network

Combustion chamber deposits are found in virtually all internal combustion engines after a few hundred hours of operation. Deposits form on cylinder, piston, and head surfaces that are in contact with fuel-air mixture ...

O'Brien, Christopher J. (Christopher John)

2001-01-01

231

ORGANIC EMISSION MEASUREMENTS VIA SMALL CHAMBER TESTING  

EPA Science Inventory

The paper discusses the measurement of organic emissions from a variety of indoor materials, using small (166 liter) environmental test chambers. The following materials were tested: adhesives, caulks, pressed wood products, floor waxes, paints, solid insecticides. For each mater...

232

Developing Cloud Chambers with High School Students  

NASA Astrophysics Data System (ADS)

The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.

Ishizuka, Ryo; Tan, Nobuaki; Sato, Shoma; Zeze, Syoji

233

Cloud chamber visualization of primary cosmic rays  

SciTech Connect

From 1948 until 1963, cloud chambers were carried to the top of the atmosphere by balloons. From these flights, which were begun by Edward P. Ney at the University of Minnesota, came the following results: discovery of heavy cosmic ray nuclei, development of scintillation and cherenkov detectors, discovery of cosmic ray electrons, and studies of solar proton events. The history of that era is illustrated here by cloud chamber photographs of primary cosmic rays.

Earl, James A. [Department of Astronomy, University of Maryland, College Park MD (United States)

2013-02-07

234

Engine Knock and Combustion Chamber Form  

NASA Technical Reports Server (NTRS)

The present report is confined to the effect of the combustion chamber shape on engine knock from three angles, namely: 1) The uniformity of flame-front movement as affected by chamber design and position of the spark plug; 2) The speed of advance of the flame as affected by turbulence and vibrations; 3) The reaction processes in the residual charge as affected by the walls.

Zinner, Karl

1939-01-01

235

Use of Freons in Bubble Chambers  

Microsoft Academic Search

The sensitive regions of several Freons in a bubble chamber have been determined. CF3Br, Freon 13B1, has been found to be sensitive at 30°C, at which temperature the equilibrium vapor pressure is only 264 psi. Because of its pleasant handling characteristics, and the fact that it can be used in any chamber designed for propane, it is suggested that it

David V. Bugg

1958-01-01

236

Quality control of ATLAS muon chambers  

E-print Network

ATLAS is a general-purpose experiment for the future Large Hadron Collider (LHC) at CERN. Its Muon Spectrometer will require ? 5500m2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5m to 15m length, embedded in a magnetic field of ? 0.5T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ? 1200 drift chambers. The performance of the MDT chambers is very much dependent on the mechanical quality of the chambers. The uniformity and stability of the performance can only be assured providing very high quality control during production. Gas tightness, high-voltage behaviour and dark currents are global parameters which are common to gas detectors. For all chambers, they will be tested immediately after the chamber assembly at every production site. Functional tests, for example radioactive source scans and cosmic-ray runs, will be performed in order to establish detailed performan...

Fabich, Adrian

237

High-pressure promoted combustion chamber  

NASA Technical Reports Server (NTRS)

In the preferred embodiment of the promoted combusiton chamber disclosed herein, a thick-walled tubular body that is capable of withstanding extreme pressures is arranged with removable upper and lower end closures to provide access to the chamber for dependently supporting a test sample of a material being evaluated in the chamber. To facilitate the real-time analysis of a test sample, several pressure-tight viewing ports capable of withstanding the simulated environmental conditions are arranged in the walls of the tubular body for observing the test sample during the course of the test. A replaceable heat-resistant tubular member and replaceable flame-resistant internal liners are arranged to be fitted inside of the chamber for protecting the interior wall surfaces of the combustion chamber during the evaluation tests. Inlet and outlet ports are provided for admitting high-pressure gases into the chamber as needed for performing dynamic analyses of the test sample during the course of an evaluation test.

Rucker, Michelle A. (inventor); Stoltzfus, Joel M. (inventor)

1991-01-01

238

Energy loss measurement in a jet chamber  

NASA Astrophysics Data System (ADS)

A full size prototype cell of a multiwire detector similar in design to the JADE[2] drift cell geometry was tested in a beam of pions and electrons at SLAC. The motivation was to explore the possibility of identifying particles through a measurement of energy loss in the HRS experiment[1]. The purpose of the test was to investigate the extent of which the measurement of the energy loss is degraded as one makes the transition from a small chamber to a full size detector. We also measured the reduction in gas gain due to saturation effects as a function of the track angles relative to the chamber wires and as a function of the total gain in the chamber. We compared our results and data reported by other groups with an empirical model calculation for the energy loss as a function of various parameters. We also developed a program to calculate expected pulse shapes for different chamber geometries. This program [10] simulates the drift process of randomly generated clusters of ionization in the electrostatic field defined by the chamber parameters. The results of this calculation are essential to evaluate the multiple hit capability of the jet chamber and its dependence on the design parameters.

Va'vra, J.; Roberts, L.; Freytag, D.; Clancey, P.

1982-12-01

239

Development of sputtered techniques for thrust chambers  

NASA Technical Reports Server (NTRS)

Techniques and materials were developed and evaluated for the fabrication and coating of advanced, long life, regeneratively cooled thrust chambers. Materials were analyzed as fillers for sputter application of OFHC copper as a closeout layer to channeled inner structures; of the materials evaluated, aluminum was found to provide the highest bond strength and to be the most desirable for chamber fabrication. The structures and properties were investigated of thick sputtered OFHC copper, 0.15 Zr-Cu, Al2O3,-Cu, and SiC-Cu. Layered structures of OFHC copper and 0.15 Zr-Cu were investigated as means of improving chamber inner wall fatigue life. The evaluation of sputtered Ti-5Al-2.5Sn, NASA IIb-11, aluminum and Al2O3-Al alloys as high strength chamber outer jackets was performed. Techniques for refurbishing degraded thrust chambers with OFHC copper and coating thrust chambers with protective ZrO2 and graded ZrO2-copper thermal barrier coatings were developed.

Mullaly, J. R.; Hecht, R. J.; Schmid, T. E.; Torrey, C. T.

1975-01-01

240

Chamber for Growing and Observing Fungi  

NASA Technical Reports Server (NTRS)

A chamber has been designed to enable growth and observation of microcolonies of fungi in isolation from the external environment. Unlike prior fungus-growing apparatuses, this chamber makes it possible to examine a fungus culture without disrupting it. Partly resembling a small picture frame, the chamber includes a metal plate having a rectangular through-thethickness opening with recesses for a top and a bottom cover glass, an inlet for air, and an inlet for water. The bottom cover glass is put in place and held there by clips, then a block of nutrient medium and a moisture pad are placed in the opening. The block is inoculated, then the top cover glass is put in place and held there by clips. Once growth is evident, the chamber can be sealed with tape. Little (if any) water evaporates past the edges of the cover glasses, and, hence there is little (if any) need to add water. A microscope can be used to observe the culture through either cover glass. Because the culture is sealed in the chamber, it is safe to examine the culture without risking contamination. The chamber can be sterilized and reused.

Pierson, Duane L.; Molina, Thomas C.

2005-01-01

241

Stability of A-150 plastic ionization chamber response over a ~30 year period  

SciTech Connect

At the NIU Institute for Neutron Therapy at Fermilab, the clinical tissue-equivalent ionization chamber response is measured every treatment day using a cesium source that was configured to match readings obtained at the National Bureau of Standards. Daily measurements are performed in air using the air-to-tissue dose conversion factors given in AAPM Report no. 7. The measured exposure calibration factors have been tabulated and graphed as a function of time from 1978 to present. For A-150 plastic ionization chambers, these factors exhibit a sinusoidal variation with a period of approximately one year and amplitude of {+-} 1%. This variation, attributable to the hygroscopic nature of A-150 plastic, is correlated with the relative humidity of the facility, and is greater than the humidity corrections for gas described in the literature. Our data suggest that chamber calibration should be performed at least weekly to accommodate these variations.

Kroc, Thomas K.; Lennox, Arlene J.; /Fermilab

2007-08-01

242

Results about HF production and bakelite analysis for the CMS Resistive Plate Chambers  

NASA Astrophysics Data System (ADS)

The formation of reactive compounds in the gas mixture during Resistive Plate Chambers (RPCs) operation at the CERN Gamma Irradiation Facility (GIF) is studied. Results from two different types of chambers are discussed: 50×50 cm2 RPC prototypes and two final CMS-RB1 chambers. The RB1 detectors were also connected to a closed loop gas system. Gas composition and possible additional impurities have been monitored in different gamma irradiation conditions both in open and closed loop modes using a gas chromatograph. Dedicated measurements for fluoride concentration in the exhausted gas line were performed at different irradiations and operation conditions using a specific electrode and a High-Performance Liquid Chromatograph. The efficiency of the purifiers system present in the closed loop in removing the F- and others impurities has also been investigated. Finally, the chemical composition of the RPC electrode surface has been analyzed using an electron microscope equipped with an EDS/X-ray.

Abbrescia, M.; Colaleo, A.; Guida, R.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Roselli, G.; Trentadue, R.; Tupputi, S.; Cavallo, N.; Fabozzi, F.; Paolucci, P.; Piccolo, D.; Polese, G.; Sciacca, C.; Belli, G.; Necchi, M.; Ratti, S.; Riccardi, C.; Torre, P.; Vitulo, P.; Anguelov, T.; Genchev, V.; Panev, B.; Piperov, S.; Sultanov, G.; Vankov, P.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.

2008-09-01

243

Versatile vacuum chamber for in situ surface X-ray scattering studies.  

PubMed

A compact portable vacuum-compatible chamber designed for surface X-ray scattering measurements on beamline ID01 of the European Synchrotron Radiation Facility, Grenoble, is described. The chamber is versatile and can be used for in situ investigation of various systems, such as surfaces, nanostructures, thin films etc., using a variety of X-ray-based techniques such as reflectivity, grazing-incidence small-angle scattering and diffraction. It has been conceived for the study of morphology and structure of semiconductor surfaces during ion beam erosion, but it is also used for the study of surface oxidation or thin film growth under ultra-high-vacuum conditions. Coherent X-ray beam experiments are also possible. The chamber is described in detail, and examples of its use are given. PMID:18552436

Carbone, Dina; Plantevin, Olivier; Gago, Raul; Mocuta, Cristian; Bikondoa, Oier; Alija, Alejandro; Petit, Lucien; Djazuli, Hamid; Metzger, Till Hartmut

2008-07-01

244

Focal Point Inside the Vacuum Chamber for Solar Thermal Propulsion  

NASA Technical Reports Server (NTRS)

Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. The 20- by 24-ft heliostat mirror (not shown in this photograph) has dual-axis control that keeps a reflection of the sunlight on an 18-ft diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. This photograph is a close-up view of a 4-in focal point inside the vacuum chamber at the MSFC Solar Thermal Propulsion Test facility. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move the Nation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth orbit, rapid travel throughout the solar system, and exploration of interstellar space.

1999-01-01

245

Team Huddle Before Lifting Phoenix into Test Chamber  

NASA Technical Reports Server (NTRS)

Spacecraft specialists huddle to discuss the critical lift of NASA's Phoenix Mars Lander into a thermal vacuum chamber.

In December 2006, the spacecraft was in a cruise configuration prior to going into environmental testing at a Lockheed Martin Space Systems facility near Denver. At all stages of assembly and testing, the spacecraft is handled with extreme care and refinement.

The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

2007-01-01

246

Design characteristics of a heat pipe test chamber  

NASA Technical Reports Server (NTRS)

LeRC has designed a heat pipe test facility which will be used to provide data for validating heat pipe computer codes. A heat pipe test chamber that uses helium gas for enhancing heat transfer was investigated. The conceptual design employs the technique of guarded heating and guarded cooling to facilitate accurate measurements of heat transfer rates to the evaporator and from the condenser. The design parameters are selected for a baseline heat pipe made of stainless steel with an inner diameter of 38.10 mm and a wall thickness of 1.016 mm. The heat pipe operates at a design temperature of 1000 K with an evaporator radial heat flux of 53 W/sq. cm.

Baker, Karl W.; Jang, J. Hoon; Yu, Juin S.

1992-01-01

247

LOTIS facility initial operational capabilities: flexible user interfaces  

NASA Astrophysics Data System (ADS)

The Large Optical Test and Integration Site (LOTIS) at the Lockheed Martin Space Systems Company in Sunnyvale, CA, has successfully reached Initial Operational Capability (IOC). LOTIS is designed for the verification and testing of optical systems. The facility consists of a large, temperature stabilized vacuum chamber that also functions as a class 10k cleanroom. Within this chamber and atop an advanced vibration-isolation bench are the 6.5 meter diameter LOTIS Collimator and Scene Generator, LOTIS alignment and support equipment. IOC included completion of the entire facility as well as operation of the LOTIS collimator in air. Wavefront properties of the collimator will be described as well as facility vibration isolation properties and turbulence levels within the collimator test chamber. User-specific test capabilities will also be addressed for two major areas of concern.

Hutchison, Sheldon B.; Bell, Raymond M., Jr.; Borota, Stephen A.; Cuzner, Gregor J.; Cochrane, Andrew T.

2010-10-01

248

Facilities Manager.  

ERIC Educational Resources Information Center

Presents a series of articles that cover a range of issues with regard to the Association of Higher Education Facilities Officers. Papers explore ways to balance natural and human settings, provide an overview of a professional leadership academy, describe the preparations for an effectiveness skills program, and outline some of the concerns…

Facilities Manager, 1998

1998-01-01

249

Music Facilities.  

ERIC Educational Resources Information Center

The layouts and specifications in this booklet are intended to assist those involved in planning music facilities for elementary and secondary schools. Drawings, room plans, and text illustrate specifications for location; space relationship; combined and separate instrumental and vocal rooms; practice rooms; and auxiliary areas. Particular…

Ontario Dept. of Education, Toronto. School Planning and Building Research Section.

250

Properties and performance of a multiwire proportional chamber  

Microsoft Academic Search

Thesis. The properties and performance of a multiwire proportional ; chamber and the corresponding calculations are discussed in detail. The ; following topics are discussed: layout of the chamber, variation of field ; intensity and degree of homogeneity as a function of chamber geometry, gas ; magnification as a function of the voltage applied and chamber geometry within ; the

Decker

1972-01-01

251

Measurement of surface alpha contamination using electret ion chambers  

Microsoft Academic Search

Electret ion chambers are inexpensive, light-weight, commercially available, passive charge-integrating devices for accurate measurement of different radiations. Performance of electret ion chambers for surface alpha contamination measurement was evaluated. Ion chambers of two types and electrets of three thicknesses were used for the study. Calibration of the electret ion chambers was performed using reference alpha standards of different energies and

S. K. Dua; S. K. Biswas; P. Szerszen; J. Boudreaux; M. A. Ebadian

1999-01-01

252

Construction and Test of a Prototype Chamber for the Upgrade of the ATLAS Muon Spectrometer  

NASA Astrophysics Data System (ADS)

Monitored drift tube chambers are used as precision tracking detectors in the muon spectrometer of the ATLAS experiment at the LHC at CERN. These chambers provide a spatial resolution of 35 ?m and a tracking efficiency of close to 100% up to background rates of 0.5 kHz/cm2, the former being limited at higher rates mainly due to space-charge effects and the latter due to the maximum drift time of 700 ns. For LHC upgrades, a faster drift tube chamber has been developed, using drift tubes with a diameter of 15 mm instead of 30 mm. The increased channel density and shorter drift time of about 200 ns raise the rate capability to about 10 kHz/cm2, while retaining the spatial resolution. A prototype chamber with trapezoidal shape consisting of 2 x 8 layers of 15 mm diameter drift tubes with an active surface of 0.8 m2 has been constructed. The prototype chamber has been tested at CERN with a 180 GeV muon beam at a SPS beam line and with cosmic ray muons at the Gamma Irradiation Facility (GIF) at high ? radiation rates.

Bittner, B.; Dubbert, J.; Kroha, H.; Loeben, J. v.; Schwegler, P.

253

Outdoor smog chamber experiments to test photochemical models. Final report May 78-May 81  

SciTech Connect

The smog chamber facility of the University of North Carolina was used in a study to provide experimental data for developing and testing kinetic mechanisms of photochemical smog formation. The smog chamber, located outdoors in rural North Carolina, is an A-frame structure covered with Teflon film. Because the chamber is partitioned into two sections, each with a volume of 156 cu m, two experiments can be conducted simultaneously. The dual chamber is operated under natural conditions of solar radiation, temperature, and relative humidity. In this study, 115 dual all-day experiments were conducted using NOx and a variety of organic species. The organic compounds investigated included various paraffins, olefins, aromatics and oxygenates, both singly and in mixtures of two or more components. In this report the data collected over the three-year period of the study are described. The experimental procedures and analytical methods used in this study and the limitations and uncertainties of the data are discussed. Guidance for modeling of the data is also given, including a detailed discussion of how to estimate photolytic rate constants from the available UV and total solar radiation data and how to treat such chamber artifacts as dilution, wall sources and losses of pollutants, and reactivity of the background air.

Feffries, H.E.; Kamens, R.M.; Sexron, K.G.; Gerhardt, A.A.

1982-04-01

254

Characteristics of a delay-line readout in a cylindrical drift chamber system  

NASA Astrophysics Data System (ADS)

This paper reports on the design, construction, and operational characteristics of a delay-line readout implemented on the cathode foils of a cylindrical drift chamber system. The readout was used to determine the position of an event along the length of the 1.74 m drift wires in the MEGA detectors used at the Los Alamos Meson Physics Facility. The performance of the system is interpreted by comparison to a PSPICE simulation, and to simple analytical models.

Barber, R.; Ahmed, M. W.; Dzemidzic, M.; Empl, A.; Hungerford, E. V.; Lan, K. J.; Wilson, J.; Cooper, M. D.; Gagliardi, C. A.; Haim, D.; Kim, G. J.; Koetke, D. D.; Tribble, R. E.; Van Ausdeln, L. A.

2002-03-01

255

Performance Of A Liquid Argon Time Projection Chamber Exposed To The WANF Neutrino Beam  

E-print Network

We present the results of the first exposure of a Liquid Argon TPC to a multi-GeV neutrino beam. The data have been collected with a 50 liters ICARUS-like chamber located between the CHORUS and NOMAD experiments at the CERN West Area Neutrino Facility (WANF). We discuss both the instrumental performance of the detector and its capability to identify and reconstruct low multiplicity neutrino interactions.

F. Arneodo et al.

2006-09-25

256

A space simulation test chamber development for the investigation of radiometric properties of materials  

NASA Technical Reports Server (NTRS)

The design, fabrication, and preliminary utilization of a thermal vacuum space simulation facility are discussed. The facility was required to perform studies on the thermal radiation properties of materials. A test chamber was designed to provide high pumping speed, low pressure, a low photon level radiation background (via high emissivity, coated, finned cryopanels), internal heat sources for rapid warmup, and rotary and linear motion of the irradiated materials specimen. The radiation detection system consists of two wideband infrared photoconductive detectors, their cryogenic coolers, a cryogenic-cooled blackbody source, and a cryogenic-cooled optical radiation modulator.

Enlow, D. L.

1972-01-01

257

NSTAR Extended Life Test Discharge Chamber Flake Analysis  

NASA Technical Reports Server (NTRS)

The Extended Life Test (ELT) of the NASA Solar Electric Propulsion Technology Readiness (NSTAR) ion thruster was concluded after 30,352 hours of operation. The ELT was conducted using the Deep Space 1 (DS1) back-up flight engine, a 30 cm diameter xenon ion thruster. Post-test inspection of the ELT engine revealed numerous contaminant flakes distributed over the bottom of the cylindrical section of the anode within the discharge chamber (DC). Extensive analyses were conducted to determine the source of the particles, which is critical to the understanding of degradation mechanisms of long life ion thruster operation. Analyses included: optical microscopy (OM) and particle length histograms, field emission scanning electron microscopy (FESEM) combined with energy dispersive spectroscopy (EDS), and atomic oxygen plasma exposure tests. Analyses of the particles indicate that the majority of the DC flakes consist of a layered structure, typically with either two or three layers. The flakes comprising two layers were typically found to have a molybdenum-rich (Mo-rich) layer on one side and a carbon-rich (C-rich) layer on the other side. The flakes comprising three layers were found to be sandwich-like structures with Mo-rich exterior layers and a C-rich interior layer. The presence of the C-rich layers indicates that these particles were produced by sputter deposition build-up on a surface external to the discharge chamber from ion sputter erosion of the graphite target in the test chamber. This contaminant layer became thick enough that particles spalled off, and then were electro-statically attracted into the ion thruster interior, where they were coated with Mo from internal sputter erosion of the screen grid and cathode components. Atomic oxygen tests provided evidence that the DC chamber flakes are composed of a significant fraction of carbon. Particle size histograms further indicated that the source of the particles was spalling of carbon flakes from downstream surfaces. Analyses of flakes taken from the downstream surface of the accelerator grid provided additional supportive information. The production of the downstream carbon flakes, and hence the potential problems associated with the flake particles in the ELT ion thruster engine is a facility induced effect and would not occur in the space environment.

deGroh, Kim K.; Banks, Bruce A.; Karniotis, Christina A.

2005-01-01

258

Design and construction of a target chamber and associated equipments for the BARC Charged Particle Detector Array  

NASA Astrophysics Data System (ADS)

A 60 cm diameter spherical high-vacuum target-chamber with side-opening hemispherical-lids, two ancillary-chambers, beam-line-tubes, tees and other high-vacuum components, and chamber-lid handling systems have been designed, constructed and installed for the Charged Particle Detector Array in BARC-TIFR Pelletron-LINAC Facility, Mumbai. This array of several tens of Si-CsI detector modules and other ancillary-detectors will be used for investigations in fusion-fission dynamics, nuclear structure at elevated temperatures and angular momenta, exotic nuclear clusters and related fields. This paper describes the unique features of the system that aid different coincidence experiments, the chamber fabrication experience and the pump-down characteristics with a turbo molecular pump. Unlike many other target chambers in use, this chamber allows multiple overall geometrical configurations to be set to reach experimental goals. For instance, by replacing a hemispherical-lid from one side with a flat-lid, the overall configuration becomes hemispherical. This way, high geometrical efficiency can be provided to an ancillary gamma detector array by allowing it to move close to target from the flat-lid side, although with some sacrifice of geometrical efficiency for charged particles. In experiments where a further improvement of geometrical efficiency for a gamma array is desired, a third compact-cylinder configuration can also be arrived at. Thinned portion of the lids of the chamber also allow neutron coincidence measurements with charged particles and gamma rays.

John, Bency; Kumar, S. Sunil; Kumar, Manish; Jangale, R. V.; Inkar, A. L.; Kinage, Lalit

2012-11-01

259

Effect of a metallized chamber upon the field response of a kicker magnet: simulations results and analytical calculations  

Microsoft Academic Search

Metallized racetrack vacuum chambers will be used in the pulsed magnets of the Austrian cancer therapy and research facility, MedAustron. It is important that the metallization does not unduly degrade field rise and fall times or the flattop of the field pulse in the kicker magnets. This was of particular concern for a tune kicker magnet, which has a specified

M J Barnes; T Fowler; M G Atanasov; T Kramer; T Stadlbauer

2012-01-01

260

Chamber LIDAR measurements of aerosolized biological simulants  

NASA Astrophysics Data System (ADS)

A chamber aerosol LIDAR is being developed to perform well-controlled tests of optical scattering characteristics of biological aerosols, including Bacillus atrophaeus (BG) and Bacillus thuringiensis (BT), for validation of optical scattering models. The 1.064 ?m, sub-nanosecond pulse LIDAR allows sub-meter measurement resolution of particle depolarization ratio or backscattering cross-section at a 1 kHz repetition rate. Automated data acquisition provides the capability for real-time analysis or recording. Tests administered within the refereed 1 cubic meter chamber can provide high quality near-field backscatter measurements devoid of interference from entrance and exit window reflections. Initial chamber measurements of BG depolarization ratio are presented.

Brown, David M.; Thrush, Evan P.; Thomas, Michael E.; Siegrist, Karen M.; Baldwin, Kevin; Quizon, Jason; Carter, Christopher C.

2009-05-01

261

Space shuttle orbit maneuvering engine reusable thrust chamber program  

NASA Technical Reports Server (NTRS)

Tests were conducted on the regenerative cooled thrust chamber of the space shuttle orbit maneuvering engine. The conditions for the tests and the durations obtained are presented. The tests demonstrated thrust chamber operation over the nominal ranges of chamber pressure mixture ratio. Variations in auxiliary film coolant flowrate were also demonstrated. High pressure tests were conducted to demonstrate the thrust chamber operation at conditions approaching the design chamber pressure for the derivative space tug application.

Pauckert, R. P.; Yost, M. C.; Tobin, R. D.

1973-01-01

262

The New LOTIS Test Facility  

NASA Technical Reports Server (NTRS)

The Large Optical Test and Integration Site (LOTIS) at the Lockheed Martin Space Systems Company in Sunnyvale, CA is designed for the verification and testing of optical systems. The facility consists of an 88 foot temperature stabilized vacuum chamber that also functions as a class 10k vertical flow cleanroom. Many problems were encountered in the design and construction phases. The industry capability to build large chambers is very weak. Through many delays and extra engineering efforts, the final product is very good. With 11 Thermal Conditioning Units and precision RTD s, temperature is uniform and stable within 1oF, providing an ideal environment for precision optical testing. Within this chamber and atop an advanced micro-g vibration-isolation bench is the 6.5 meter diameter LOTIS Collimator and Scene Generator, LOTIS alignment and support equipment. The optical payloads are also placed on the vibration bench in the chamber for testing. This optical system is designed to operate in both air and vacuum, providing test imagery in an adaptable suite of visible/near infrared (VNIR) and midwave infrared (MWIR) point sources, and combined bandwidth visible-through-MWIR point sources, for testing of large aperture optical payloads. The heart of the system is the LOTIS Collimator, a 6.5m f/15 telescope, which projects scenes with wavefront errors <85 nm rms out to a 0.75 mrad field of view (FOV). Using field lenses, performance can be extended to a maximum field of view of 3.2 mrad. The LOTIS Collimator incorporates an extensive integrated wavefront sensing and control system to verify the performance of the system.

Bell, R. M.; Cuzner, G.; Eugeni, C.; Hutchison, S. B.; Merrick, A. J.; Robins, G. C.; Bailey, S. H.; Ceurden, B.; Hagen, J.; Kenagy, K.; Martin, H. M.; Tuell, M.; Ward, M.; West, S. C.

2008-01-01

263

CCN comparisons of static diffusion chambers  

NASA Technical Reports Server (NTRS)

Nine CCN counters of the static diffusion (SDC) type were compared with one another and with continuous flow diffusion (CFD) chambers. The nine SDCs showed a considerable amount of variation, largely attributable to newness and/or lack of prior calibration of some units. The five more consistent instruments agreed quite well, to within at least 20 percent of the NRL mobility analyzer and to within 10 percent at 1 percent supersaturation. There was satisfactory agreement between the more reliable SDC and CFD chambers.

Jiusto, J. E.; Ruskin, R. E.; Gagin, A.

1981-01-01

264

Secondary organic aerosol formation from gasoline vehicle emissions in a new mobile environmental reaction chamber  

NASA Astrophysics Data System (ADS)

We present a new mobile environmental reaction chamber for the simulation of the atmospheric aging of aerosols from different emissions sources without limitation from the instruments or facilities available at any single site. The chamber can be mounted on a trailer for transport to host facilities or for mobile measurements. Photochemistry is simulated using a set of 40 UV lights (total power 4 KW). Characterisation of the emission spectrum of these lights shows that atmospheric photochemistry can be accurately simulated over a range of temperatures from -7-25 °C. A photolysis rate of NO2, JNO2, of (8.0 ± 0.7) × 10-3 molecules cm-3 s-1 was determined at 25 °C. Further, we present the first application of the mobile chamber and demonstrate its utility by quantifying primary organic aerosol (POA) emission and secondary organic aerosol (SOA) production from a Euro 5 light duty gasoline vehicle. Exhaust emissions were sampled during the New European Driving Cycle (NEDC), the standard driving cycle for European regulatory purposes, and injected into the chamber. The relative concentrations of oxides of nitrogen (NOx) and total hydrocarbon (THC) during the aging of emissions inside the chamber were controlled using an injection system developed as a part of the new mobile chamber set up. Total OA (POA + SOA) emission factors of (370 ± 18) × 10-3 g kg-1 fuel, or (14.6 ± 0.8) × 10-3 g km-1, after aging, were calculated from concentrations measured inside the smog chamber during two experiments. The average SOA/POA ratio for the two experiments was 15.1, a much larger increase than has previously been seen for diesel vehicles, where smog chamber studies have found SOA/POA ratios of 1.3-1.7. Due to this SOA formation, carbonaceous particulate matter (PM) emissions from a gasoline vehicle may approach those of a diesel vehicle of the same class. Furthermore, with the advent of emission controls requiring the use of diesel particle filters, gasoline vehicle emissions could become a far larger source of ambient PM than diesel vehicles. Therefore this large increase in the PM mass of gasoline vehicle aerosol emissions due to SOA formation has significant implications for our understanding of the contribution of on-road vehicles to ambient aerosols and merits further study.

Platt, S. M.; El Haddad, I.; Zardini, A. A.; Clairotte, M.; Astorga, C.; Wolf, R.; Slowik, J. G.; Temime-Roussel, B.; Marchand, N.; Ježek, I.; Drinovec, L.; Mo?nik, G.; Möhler, O.; Richter, R.; Barmet, P.; Bianchi, F.; Baltensperger, U.; Prévôt, A. S. H.

2012-10-01

265

The Holifield Heavy Ion Research Facility  

SciTech Connect

Development of the Holifield facility has continued with resulting improvements in the number of ion species provided, ion energy for tandem-only operations, and utilization efficiency. The Holifield Heavy Ion Research Facility (HHIRF) is located at the Oak Ridge National Laboratory and operated as a national user facility for research in heavy ion science. The facility operates two accelerators: an NEC pelletron tandem accelerator designed to operate at terminal potentials up to 25 MV and the Oak Ridge Isochronous Cyclotron (ORIC) which has been modified to serve as an energy booster for beams from the tandem accelerator. The principal experimental devices of the facility include a broad range spectrograph (ME/q/sup 2/ = 225) equipped with a vertical drift chamber detector system, a 4..pi.. spin spectrometer equipped with 72 NaI detectors (Ge detectors and BGO compton-suppression units can be used in place of the NaI detectors), a time-of-flight spectrometer, a 1.6-m scattering chamber, a heavy-ion/light-ion detector (HILI) which will be used for studying inverse reactions, a split-pole spectrograph, and a velocity filter. In this report, we will discuss our recent development activities, operational experience, and future development plans.

Jones, C.M.; Alton, G.D.; Ball, J.B.; Biggerstaff, J.A.; Dowling, D.T.; Erb, K.A.; Haynes, D.L.; Hoglund, D.E.; Hudson, E.D.; Juras, R.C.

1987-01-01

266

Recent Improvements to the Acoustical Testing Laboratory at the NASA Glenn Research Center  

NASA Technical Reports Server (NTRS)

The Acoustical Testing Laboratory (ATL) consists of a 27- by 23- by 20-ft (height) convertible hemi/anechoic chamber and separate sound-attenuating test support enclosure. Absorptive fiberglass wedges in the test chamber provide an anechoic environment down to 100 Hz. A spring-isolated floor system affords vibration isolation above 3 Hz. These specifications, along with very low design background levels, enable the acquisition of accurate and repeatable acoustical measurements on test articles that produce very low sound pressures. Removable floor wedges allow the test chamber to operate in either a hemi-anechoic or anechoic configuration, depending on the size of the test article and the specific test being conducted. The test support enclosure functions as a control room during normal operations. Recently improvements were accomplished in support of continued usage of the ATL by NASA programs including an analysis of the ultra-sonic characteristics. A 3-D traverse system inside the chamber was utilized for acquiring acoustic data for these tests. The traverse system drives a linear array of 13, 1/4 in.-microphones spaced 3 in. apart (36 in. span). An updated data acquisition system was also incorporated into the facility.

Podboy, Devin M.; Mirecki, Julius H.; Walker, Bruce E.; Sutliff, Daniel L.

2014-01-01

267

The Biological Flight Research Facility  

NASA Technical Reports Server (NTRS)

NASA Ames Research Center (ARC) is building a research facility, the Biological Flight Research Facility (BFRF), to meet the needs of life scientists to study the long-term effects of variable gravity on living systems. The facility will be housed on Space Station Freedom and is anticipated to operate for the lifetime of the station, approximately thirty years. It will allow plant and animal biologists to study the role of gravity, or its absence, at varying gravity intensities for varying periods of time and with various organisms. The principal difference between current Spacelab missions and those on Space Station Freedom, other than length of mission, will be the capability to perform on-orbit science procedures and the capability to simulate earth gravity. Initially the facility will house plants and rodents in habitats which can be maintained at microgravity or can be placed on a 2.5 meter diameter centrifuge. However, the facility is also being designed to accommodate future habitats for small primates, avian, and aquatic specimens. The centrifuge will provide 1 g for controls and will also be able to provide gravity from 0.01 to 2.0 g for threshold gravity studies as well as hypergravity studies. Included in the facility are a service unit for providing clean chambers for the specimens and a glovebox for manipulating the plant and animal specimens and for performing experimental protocols. The BFRF will provide the means to conduct basic experiments to gain an understanding of the effects of microgravity on the structure and function of plants and animals, as well as investigate the role of gravity as a potential countermeasure for the physiological changes observed in microgravity.

Johnson, Catherine C.

1993-01-01

268

Recent Advances in Chamber Science and Technology  

E-print Network

Recent Advances in Chamber Science and Technology Mohamed Abdou April 8, 2002ISFNT-6 San Diego, USA;HYLIFE-II ALPS/APEX NSTX Li module Liquid Wall Science & Technology are being Advanced in Several MFE temperatures Flinabe is an attractive alternative to flibe because it has low melting point (240-310 C

California at Los Angeles, University of

269

Multiphysics Nuclear Thermal Rocket Thrust Chamber Analysis  

NASA Technical Reports Server (NTRS)

The objective of this effort is t o develop an efficient and accurate thermo-fluid computational methodology to predict environments for hypothetical thrust chamber design and analysis. The current task scope is to perform multidimensional, multiphysics analysis of thrust performance and heat transfer analysis for a hypothetical solid-core, nuclear thermal engine including thrust chamber and nozzle. The multiphysics aspects of the model include: real fluid dynamics, chemical reactivity, turbulent flow, and conjugate heat transfer. The model will be designed to identify thermal, fluid, and hydrogen environments in all flow paths and materials. This model would then be used to perform non- nuclear reproduction of the flow element failures demonstrated in the Rover/NERVA testing, investigate performance of specific configurations and assess potential issues and enhancements. A two-pronged approach will be employed in this effort: a detailed analysis of a multi-channel, flow-element, and global modeling of the entire thrust chamber assembly with a porosity modeling technique. It is expected that the detailed analysis of a single flow element would provide detailed fluid, thermal, and hydrogen environments for stress analysis, while the global thrust chamber assembly analysis would promote understanding of the effects of hydrogen dissociation and heat transfer on thrust performance. These modeling activities will be validated as much as possible by testing performed by other related efforts.

Wang, Ten-See

2005-01-01

270

OUTDOOR SMOG CHAMBER EXPERIMENTS USING AUTOMOBILE EXHAUST  

EPA Science Inventory

Outdoor smog chamber experiments using automobile exhaust were performed in this study. The purpose of the study was to provide a data base that modelers could use to develop new, improved mechanisms for use in the Empirical Kinetics Modeling Approach (EKMA). Thirty-three dual sm...

271

Simple Temperature Regulator for a Cold Chamber  

NASA Technical Reports Server (NTRS)

Electronic control circuit holds cold chamber at selectable temperature and lights warning light if temperature exceeds predetermined level amplifiers. Temperature regulator circuit and warning-light circuit are independent of one another, but reference-level potentiometers are ganged. Temperature control circuit includes some feedback to prevent refrigeration unit from cycling on and off too frequently.

Redmond, W. G.

1982-01-01

272

Simulating design storms with water chamber testing  

SciTech Connect

The most commonly-used standard method of testing a masonry wall's leakage performance in the laboratory is the ASTM Standard Test Method for Water Penetration and Leakage Through Masonry (C 1389) water chamber test. The apparatus from this test has been modified for field use by various individuals but no standard provisions for field use have yet been developed. ASTM is currently considering such a standard test method for field water chamber testing. The purpose, interpretation of results, significance, and procedures of the field test have been questioned and criticized in the past. It is the purpose of this paper to address wind-driven rainfall simulation using the chamber test in the field or laboratory. Water intrusion into and through a masonry facade is affected by air pressure, momentum, gravity, capillary action, and other basic scientific principles. Analysis of the driving forces behind water penetration is presented to show the relationship between these phenomena and testing variables. Through the use of the concepts and procedures presented in this paper, a more thorough understanding of realistic water testing of masonry structures and a more accurate determination of a building's performance with regard to water penetration using the water chamber test method will be available.

Galitz, C.L.; Whitlock, A.R.

1999-07-01

273

Lifetime tests for MAC vertex chamber  

SciTech Connect

A vertex chamber for MAC was proposed to increase precision in the measurement of the B hadron and tau lepton lifetimes. Thin-walled aluminized mylar drift tubes were used for detector elements. A study of radiation hardness was conducted under the conditions of the proposed design using different gases and different operating conditions. (LEW)

Nelson, H.N.

1986-07-01

274

A reusable prepositioned ATP reaction chamber  

NASA Technical Reports Server (NTRS)

Luminescence biometer detects presence of life by means of light-emitting chemical reaction of luciferin and luciferase with adenosine triphosphate (ATP) that occurs in all living cells. Amount of light in reaction chamber is measured to determine presence and extent of life.

Hoffman, D. G.

1972-01-01

275

PAINT COATINGS: CONTROLLED FIELD AND CHAMBER EXPERIMENTS  

EPA Science Inventory

To determine the impact of pollution levels on the weathering rates of coatings, laboratory chamber experiments and controlled field exposures at North Carolina and Ohio sites were conducted in such a manner to separate the contributions due to dry deposition, wet deposition, pre...

276

HERL BIOLOGICAL EXPOSURE CHAMBER CONCEPTUAL DESIGN  

EPA Science Inventory

Because of the current interest in biotesting of potentially hazardous air pollutants, the Health Effects Research Laboratory (HERL) of EPA/RTP has contracted Radian to design biological exposure chambers that can be used to expose text organisms to the secondary aerosol effluent...

277

CHAMBER TECHNOLOGY FY 02 / 03 / 04  

E-print Network

metal MHD and high Prandtl fluid flow experiments to address the critical data needs for plasma Thermomechanics (involves 12 U.S. institutions) (Collaborative Program with Japan) (Collaborative Program with IEA and Japan) #12;Chamber Technology: Scope APEX (involves 12 US institutions) q Perform free-surface liquid

Abdou, Mohamed

278

Monitoring the Atmosphere in an Anaerobic Chamber  

PubMed Central

The Couloximeter, a fuel cell designed to measure trace amounts of oxygen, was used to monitor the atmosphere in an anaerobic chamber. The device, easy to operate and to maintain, allowed both major and minor fluctuations in oxygen concentration to be measured. Using a hose attached to the outlet within the box, defective (ruptured) gloves were consistently distinguishable from intact gloves. PMID:16350004

Sudo, Sara Z.; Hersch, Paul A.

1974-01-01

279

Charm baryons: observed in bubble chambers  

SciTech Connect

The production and decay of charm baryons as observed in bubble chambers and initiated, as it happens, by neutrinos are reviewed. In particular, the experimental data with respect to the ..lambda../sub c//sup +/, sigma/sub c//sup + +/, and sigma/sub c//sup +/ charm baryons are discussed. 8 figures, 2 tables.

Samios, N P

1980-01-01

280

Development of in-vessel neutron monitor using micro-fission chambers for ITER  

NASA Astrophysics Data System (ADS)

A neutron monitor using micro-fission chambers to be installed inside the vacuum vessel has been designed for the International Thermonuclear Experimental Reactor (ITER). The monitoring system needs to be insensitive to the changes of the plasma position and the profile, and the locations behind upper and lower outboard blankets were selected as appropriate based on the neutron transport calculations with the Monte Carlo code for neutron and photon transport (MCNP). Employing both pulse counting and Campbelling modes in the electronics, the ITER requirement of 107 dynamic range with 1 ms temporal resolution will be accomplished. The system meets the 10% accuracy required for the fusion power monitor. A set of a 235U micro-fission chamber with 12 mg UO2 and a fissile-material-free "blank" detector to eliminate noise issues arising from ? rays, etc. were fabricated based on the design. The vacuum leak rate of the chamber with the mineral insulated (MI) cable, resistances between the central conductor and outer sheath, and mechanical strength up to 50 G acceleration were tested to meet the design criteria. The output signals for ? rays were measured with the 60Co ?-ray irradiation facility at Japan Atomic Energy Research Institute (JAERI)-Takasaki and the influence was estimated to be less than 0.1% of the signals for neutrons. Excellent linearities between count rates, square of Campbelling voltage, and neutron fluxes were confirmed in the temperature range from 20 °C (room) to 250 °C with the Fusion Neutronics Source (FNS) facility of JAERI. The influence of the surrounding material was studied with the shielding blanket mock-up, and it was verified that the chamber provides an effective response although the sensitivity was enhanced by slow-downed neutrons. As a result, it was concluded that the present micro-fission chamber is applicable to ITER power monitoring.

Yamauchi, M.; Nishitani, T.; Ochiai, K.; Morimoto, Y.; Hori, J.; Ebisawa, K.; Kasai, S.; Walker, C.

2003-03-01

281

ORNL irradiation creep facility  

SciTech Connect

A machine was developed at ORNL to measure the rates of elongation observed under irradiation in stressed materials. The source of radiation is a beam of 60 MeV alpha particles from the Oak Ridge Isochronous Cyclotron (ORIC). This choice allows experiments to be performed which simulate the effects of fast neutrons. A brief review of irradiation creep and experimental constraints associated with each measurement technique is given. Factors are presented which lead to the experimental choices made for the Irradiation Creep Facility (ICF). The ICF consists of a helium-filled chamber which houses a high-precision mechanical testing device. The specimen to be tested must be thermally stabilized with respect to the temperature fluctuations imposed by the particle beam which passes through the specimen. Electrical resistance of the specimen is the temperature control parameter chosen. Very high precision in length measurement and temperature control are required to detect the small elongation rates relevant to irradiation creep in the test periods available (approx. 1 day). The apparatus components and features required for the above are presented in some detail, along with the experimental procedures. The damage processes associated with light ions are discussed and displacement rates are calculated. Recent irradiation creep results are given, demonstrating the suitability of the apparatus for high resolution experiments. Also discussed is the suitability of the ICF for making high precision thermal creep measurements.

Reiley, T.C.; Auble, R.L.; Beckers, R.M.; Bloom, E.E.; Duncan, M.G.; Saltmarsh, M.J.; Shannon, R.H.

1980-09-01

282

Europlanet Research Infrastructure: Planetary Simulation Facilities  

NASA Astrophysics Data System (ADS)

EuroPlanet The Europlanet Research Infrastructure consortium funded under FP7 aims to provide the EU Planetary Science community greater access for to research infrastructure. A series of networking and outreach initiatives will be complimented by joint research activities and the formation of three Trans National Access distributed service laboratories (TNA's) to provide a unique and comprehensive set of analogue field sites, laboratory simulation facilities, and extraterrestrial sample analysis tools. Here we report on the infrastructure that comprises the second TNA; Planetary Simulation Facilities. 11 laboratory based facilities are able to recreate the conditions found in the atmospheres and on the surfaces of planetary systems with specific emphasis on Martian, Titan and Europa analogues. The strategy has been to offer some overlap in capabilities to ensure access to the highest number of users and to allow for progressive and efficient development strategies. For example initial testing of mobility capability prior to the step wise development within planetary atmospheres that can be made progressively more hostile through the introduction of extreme temperatures, radiation, wind and dust. Europlanet Research Infrastructure Facilties: Mars atmosphere simulation chambers at VUA and OU These relatively large chambers (up to 1 x 0.5 x 0.5 m) simulate Martian atmospheric conditions and the dual cooling options at VUA allows stabilised instrument temperatures while the remainder of the sample chamber can be varied between 220K and 350K. Researchers can therefore assess analytical protocols for instruments operating on Mars; e.g. effect of pCO2, temperature and material (e.g., ± ice) on spectroscopic and laser ablation techniques while monitoring the performance of detection technologies such as CCD at low T & variable p H2O & pCO2. Titan atmosphere and surface simulation chamber at OU The chamber simulates Titan's atmospheric composition under a range of pressures and temperatures and through provision of external UV light and or electrical discharge can be used to form the well known Titan Aerosol species, which can subsequently be analysed using one of several analytical techniques (UV-Vis, FTIR and mass spectrometry). Simulated surfaces can be produced (icy surfaces down to 15K) and subjected to a variety of light and particles (electron and ion) sources. Chemical and physical changes in the surface may be explored using remote spectroscopy. Planetary Simulation chamber for low density atmospheres INTA-CAB The planetary simulation chamber-ultra-high vacuum equipment (PSC-UHV) has been designed to study planetary surfaces and low dense atmospheres, space environments or any other hypothetic environment at UHV. Total pressure ranges from 7 mbar (Martian conditions) to 5x10-9 mbar. A residual gas analyzer regulates gas compositions to ppm precision. Temperature ranges from 4K to 325K and most operations are computer controlled. Radiation levels are simulated using a deuterium UV lamp, and ionization sources. 5 KV electron and noble-gas discharge UV allows measurement of IR and UV spectra and chemical compositions are determined by mass spectroscopy. Planetary Simulation chamber for high density planetary atmospheres at INTA-CAB The facility allows experimental study of planetary environments under high pressure, and was designed to include underground, seafloor and dense atmosphere environments. Analytical capabilities include Raman spectra, physicochemical properties of materials, e.a. thermal conductivity. P-T can be controlled as independent variables to allow monitoring of the tolerance of microorganisms and the stability of materials and their phase changes. Planetary Simulation chamber for icy surfaces at INTA-CAB This chamber is being developed to the growth of ice samples to simulate the chemical and physical properties of ices found on both planetary bodies and their moons. The goal is to allow measurement of the physical properties of ice samples formed under planetary conditions to assess how rheolo

Davies, G. R.; Mason, N. J.; Green, S.; Gómez, F.; Prieto, O.; Helbert, J.; Colangeli, L.; Srama, R.; Grande, M.; Merrison, J.

2008-09-01

283

Anterior chamber fixation of a posterior chamber intraocular lens: A novel technique  

PubMed Central

We aimed to evaluate the implantation of a posterior chamber intraocular lens (IOL) in the anterior chamber (AC) with the haptics passing through two iridectomies to the posterior chamber. A total of 33 eyes of 33 patients with inadequate posterior capsular support due to either previous aphakia or posterior capsular rupture during cataract extraction were included in the study. A double iridectomy was performed on all patients using a vitrectomy probe on the midperiphery of the iris. IOLs were implanted in the AC, and the haptics were passed through the iridectomies to the posterior chamber. The mean follow-up time was 25.3 months. AC hemorrhage occurred in five patients during the iridectomy procedure. Corneal edema was detected in eight of 14 patients with primary IOL insertions. Haptic dislocation was detected in only one patient. This technique may be a good alternative to scleral-fixated IOL implantation in eyes with aphakia. PMID:24817750

Kükner, A ?ahap; Alagöz, Gürsoy; Erdurmu?, Mesut; Serin, Didem; Do?an, Ümit; Y?lmaz, Turgut

2014-01-01

284

A combination drift chamber\\/pad chamber for very high readout rates  

Microsoft Academic Search

Details of the construction of high-rate, mid-sized (1-m×2-m) pad chambers, intended for use in Fermi National Accelerator Laboratory (FNAL) experiment E-771, are described. Each gas volume module represents a chamber doublet: two identical anode wire planes, two transverse strip planes, and two pad planes. Wire signals, from 8-mm square cells, are recorded via TDCs; corresponding stripe and pad image signals

L. Spiegel; T. Alexopoulos; L. Antoniazzi; M. Arenton; C. Ballagh; H. Bingham; A. Blankman; M. Block; A. Boden; S. Borodin; J. Budagov; Z. L. Cao; G. Cataldi; T. Y. Chen; K. Clark; D. Cline; S. Conetti; M. Cooper; G. Corti; B. Cox; P. Creti; E. Dukes; C. Durandet; V. Elia; A. Erwin; L. Fortney; V. Golovatyuk; E. Gorini; F. Grancagnolo; M. Haire; P. Hanlet; M. He; G. Introzzi; M. Jenkins; J. Jennings; D. Judd; T. Kaeding; W. Kononenko; W. Kowald; A. Lanza; K. Lau; T. LeCompte; G. Liguori; J. Lys; P. Mazur; A. McManus; S. Misawa; G. Mo; C. T. Murphy; K. Nelson; M. Newcomer; M. Panareo; S. Ramachandran; M. Recagni; J. Rhoades; J. Rosen; J. Segal; W. Selove; R. P. Smith; J. Sun; S. Tokar; P. Torre; J. Trischuk; T. Trojak; E. Tsyganov; L. Turnbull; R. VanBerg; D. Wagoner; C. Wang; C. Wei; W. Yang; N. Yao; T. Yao; N. Zhang; S. N. Zhang; B. Zou

1991-01-01

285

CONTAINMENT SYSTEM, SPRAY CHAMBER, LOOKING NORTH WITH MIST COOLING MOLTEN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONTAINMENT SYSTEM, SPRAY CHAMBER, LOOKING NORTH WITH MIST COOLING MOLTEN STEEL SLABS AS THEY PROGRESS THROUGH THIS CHAMBER. - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

286

Dark Matter Time Projection Chamber : Recent R&D Results  

E-print Network

The Dark Matter Time Projection Chamber collaboration recently reported a dark matter limit obtained with a 10 liter time projection chamber filled with CF[subscript 4] gas. The 10 liter detector was capable of 2D tracking ...

Battat, J.B.R.

287

30 CFR 57.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2013 CFR

...AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill...

2013-07-01

288

30 CFR 57.7807 - Flushing the combustion chamber.  

...AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill...

2014-07-01

289

30 CFR 56.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2011 CFR

...SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has...

2011-07-01

290

30 CFR 56.7807 - Flushing the combustion chamber.  

...SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has...

2014-07-01

291

30 CFR 56.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2012 CFR

...SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has...

2012-07-01

292

30 CFR 57.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2012 CFR

...AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill...

2012-07-01

293

30 CFR 57.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2011 CFR

...AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill...

2011-07-01

294

30 CFR 56.7807 - Flushing the combustion chamber.  

Code of Federal Regulations, 2013 CFR

...SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has...

2013-07-01

295

Utilizing Chamber Data for Developing and Validating Climate Change Models  

NASA Technical Reports Server (NTRS)

Controlled environment chambers (e.g. growth chambers, SPAR chambers, or open-top chambers) are useful for measuring plant ecosystem responses to climatic variables and CO2 that affect plant water relations. However, data from chambers was found to overestimate responses of C fluxes to CO2 enrichment. Chamber data may be confounded by numerous artifacts (e.g. sidelighting, edge effects, increased temperature and VPD, etc) and this limits what can be measured accurately. Chambers can be used to measure canopy level energy balance under controlled conditions and plant transpiration responses to CO2 concentration can be elucidated. However, these measurements cannot be used directly in model development or validation. The response of stomatal conductance to CO2 will be the same as in the field, but the measured response must be recalculated in such a manner to account for differences in aerodynamic conductance, temperature and VPD between the chamber and the field.

Monje, Oscar

2012-01-01

296

DESIGN, CONSTRUCTION, AND EVALUATION OF A CHAMBER FOR AEROBIOLOGY  

EPA Science Inventory

A chamber was designed and constructed for aeromicrobiology applications. An ultraviolet (UV) radiation source was incorporated to sterilize the chamber between trials. Twelve bacterial species originally isolated from air samples and obtained from the American Type Culture Colle...

297

On-Site Wastewater Treatment Systems: Leaching Chambers  

E-print Network

Two-compartment septic tank Leaching chamber Soil absorption field On-site wastewater treatment systems Leaching chambers Bruce Lesikar and Russell Persyn Extension Agricultural Engineering Specialist, Extension Assistant-Water Conservation...

Lesikar, Bruce J.

2000-02-04

298

Chamber Design For Slow Nucleation Protein Crystal Growth  

NASA Technical Reports Server (NTRS)

Multiple-chamber dialysis apparatus grows protein crystals on Earth or in microgravity with minimum of intervention by technician. Use of multiple chambers provides gradation of nucleation and growth rates.

Pusey, Marc Lee

1995-01-01

299

Automatic Ionization Measurement in Avalanche Chamber Pictures  

NASA Astrophysics Data System (ADS)

The experiment WA44 at the CERN SPS, "Search for quarks in high-energy neutrino interactions", is equipped with a large volume (2.35 × 1.25 × 0.6 m3) streamer chamber for the primary ionization measurement of charged tracks. The streamer chamber, filled with a He-Ne mixture, is operated in the avalanche mode. Image intensifiers are used to record the event on a photographic film. The pictures are automatically scanned by a Flying-Spot-Digitizer and the scanning data are stored on magnetic tape. In this paper the analysis of the FSD data, i.e., the track finding method and the measurement of the avalanche density, are described. The results obtained with this automatic method show that both the efficiency of track finding and the reliability of ionization measurement are good, down to avalanche densities as low as 1/10 of the ionization expected for minimum ionizing charge-one particles.

Basile, M.; Romeo, G. Cara; Castelvetri, A.; Cifarelli, L.; Contin, A.; D'Ali, G.; Di Cesare, P.; Esposito, B.; Favale, L.; Giusti, P.; Laakso, I.; Marrian, C.; Masetti, M.; Massam, T.; Nania, R.; Palmonari, F.; Rohrbach, F.; Rossi, V.; Sartorelli, G.; Spinetti, M.; Susinno, G.; Valenti, G.; Votano, L.; Zichichi, A.

1981-04-01

300

Proposal of a growth chamber for growing Super-Dwarf Rice in Space Agriculture  

NASA Astrophysics Data System (ADS)

Space agriculture needs to be considered to supply food for space crew who stay in space over an extended time period. So far crops such as wheat, onion, oat, pea and lettuce grew to explore the possibility of space agriculture. Although rice is a staple food for most of the world, research on rice cultivation in space has not been done much. Rice grains are nutrient-rich with carbohydrate, protein and dietary fiber. Moreover, rice is a high yield crop and harvested grains have a long shelf life. However, the plant height of standard rice cultivars is relatively long, requiring much space. In addition, rice plants require higher light intensities for greater yield. For these reasons, it is difficult to establish facilities for rice culture in a limited space with a low cost. We propose to employee a super-dwarf cultivar and a small growth chamber with a new type of LEDs. The super-dwarf rice is a short-grain japonica variety and the plant height is approximately 20 cm that is one-fifth as tall as standard cultivars. The LED light used as a light source for this study can provide full spectrum of 380 nm to 750 nm. Air temperature and humidity were controlled by a Peltier device equipped in the chamber. The characteristics of the new type of LEDs and other equipments of the chamber and the ground based performance of super-dwarf rice plants grown in the chamber will be reported.

Hirai, Hiroaki; Kitaya, Yoshiaki; Tsukamoto, Koya; Yamashita, Youichirou; Hirai, Takehiro

301

The U.S. Lab is placed in vacuum chamber for leak test  

NASA Technical Reports Server (NTRS)

With the lid of the three-story vacuum chamber in place, a worker on top checks release of the cables. Inside the chamber is the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

2000-01-01

302

Reduce Steam Trap Failures at Chambers Works  

E-print Network

Reduce Steam Trap Failures at Chambers Works GB/BB Name: Cyndi Kouba Mentor/MBB: Andrew Degraff Team Members Michael Crowley(Site Energy Lead), (Charlie) Flanigan (Aramids-maintenance), Ben Snyder (Aramids-ATO), Michael Scruggs (Central... Maintenance Mechanic), Rick Ragsdale (Fluor), Joyce Finkle (PC), Denis P Humphreys (Fluoroproducts), Jack Hemmert, Charlie Brown 10/20/2010 2 Steam trap failures are nothing new Steam trap programs are nothing new WHAT makes this program have such a huge...

Kouba, C.

303

The KLOE drift chamber VCI 2001  

Microsoft Academic Search

The main goal of the KLOE experiment at the Frascati DA?NE ??factory is the study CP violation in kaon decays. The tracking device of the experiment is a drift chamber whose dimensions, 4m of diameter and 3.3m length, provide a large acceptance volume for the decay products of low momentum KL (?L=3.4m). A complete stereo geometry with 12.582 cells arranged

M. Adinolfi; A. Aloisio; F. Ambrosino; A. Andryakov; A. Antonelli; M. Antonelli; F. Anulli; C. Bacci; A. Bankamp; G. Barbiellini; F. Bellini; G. Bencivenni; S. Bertolucci; C. Bini; C. Bloise; V. Bocci; F. Bossi; P. Branchini; S. A Bulychjov; G. Cabibbo; A. Calcaterra; R. Caloi; P. Campana; G. Capon; G. Carboni; A. Cardini; M. Casarsa; G. Cataldi; F. Ceradini; F. Cervell; F. Cevenini; G. Chiefari; P. Ciambrone; S. Conetti; S. Conticelli; E De Lucia; G De Robertis; R De Sangro; P De Simone; G De Zorzi; S Dell'Agnello; A. Denig; A. Di Domenico; C. Di Donato; S Di Falco; A. Doria; E. Drago; V. Elia; O. Erriquez; A. Farilla; G. Felici; A. Ferrari; M. L Ferrer; G. Finocchiaro; C. Forti; A. Franceschi; P. Franzini; M. L Gao; C. Gatti; P. Gauzzi; S. Giovannella; V. Golovatyuk; E. Gorini; F. Grancagnolo; W. Grandegger; E. Graziani; P. Guarnaccia; U. v. Hagel; H. G Han; S. W Han; X. Huang; M. Incagli; L. Ingrosso; Y. Y. Jang; W. Kim; W. Kluge; V. Kulikov; F. Lacava; G. Lanfranchi; J. Lee-Franzini; F. Lomtadze; C. Luisi; C. S Mao; M. Martemianov; M. Matsyuk; W. Mei; L. Merola; R. Messi; S. Miscetti; A. Moalem; S. Moccia; M. Moulson; S. Mueller; F. Murtas; M. Napolitano; A. Nedosekin; M. Panareo; L. Pacciani; P. Pages; M. Palutan; L. Paoluzi; E. Pasqualucci; L. Passalacqua; M. Passaseo; A. Passeri; V. Patera; E. Petrolo; G. Petrucci; D. Picca; G. Pirozzi; C. Pistillo; M. Pollack; L. Pontecorvo; M. Primavera; F. Ruggieri; P. Santangelo; E. Santovetti; G. Saracino; R. D Schamberger; C. Schwick; B. Sciascia; A. Sciubba; F. Scuri; I. Sfiligoi; J. Shan; P. Silano; T. Spadaro; S. Spagnolo; E. Spiriti; C. Stanescu; G. L Tong; L. Tortora; E. Valente; P. Valente; B. Valeriani; G. Venanzoni; S. Veneziano; Y. Wu; Y. G Xie; P. P. Zhao; Y. Zhou

2002-01-01

304

CFD Code Survey for Thrust Chamber Application  

NASA Technical Reports Server (NTRS)

In the quest fo find analytical reference codes, responses from a questionnaire are presented which portray the current computational fluid dynamics (CFD) program status and capability at various organizations, characterizing liquid rocket thrust chamber flow fields. Sample cases are identified to examine the ability, operational condition, and accuracy of the codes. To select the best suited programs for accelerated improvements, evaluation criteria are being proposed.

Gross, Klaus W.

1990-01-01

305

Multi-chamber controllable heat pipe  

NASA Technical Reports Server (NTRS)

A temperature controllable heat pipe switching device is reported. It includes separate evaporating and condensing chambers interconnected by separate vapor flow and liquid return conduits. The vapor flow conduit can be opened or closed to the flow of vapor, whereas the liquid return conduit blocks vapor flow at all times. When the vapor flow path is open, the device has high thermal conductivity, and when the vapor flow path is blocked the device has low thermal conductivity.

Shlosinger, A. P. (inventor)

1970-01-01

306

An Experimental Study of Upward Burning Over Long Solid Fuels: Facility Development and Comparison  

NASA Technical Reports Server (NTRS)

As NASA's mission evolves, new spacecraft and habitat environments necessitate expanded study of materials flammability. Most of the upward burning tests to date, including the NASA standard material screening method NASA-STD-6001, have been conducted in small chambers where the flame often terminates before a steady state flame is established. In real environments, the same limitations may not be present. The use of long fuel samples would allow the flames to proceed in an unhindered manner. In order to explore sample size and chamber size effects, two large chambers were developed at NASA GRC under the Flame Prevention, Detection and Suppression (FPDS) project. The first was an existing vacuum facility, VF-13, located at NASA John Glenn Research Center. This 6350 liter chamber could accommodate fuels sample lengths up to 2 m. However, operational costs and restricted accessibility limited the test program, so a second laboratory scale facility was developed in parallel. By stacking additional two chambers on top of an existing combustion chamber facility, this 81 liter Stacked-chamber facility could accommodate a 1.5 m sample length. The larger volume, more ideal environment of VF-13 was used to obtain baseline data for comparison with the stacked chamber facility. In this way, the stacked chamber facility was intended for long term testing, with VF-13 as the proving ground. Four different solid fuels (adding machine paper, poster paper, PMMA plates, and Nomex fabric) were tested with fuel sample lengths up to 2 m. For thin samples (papers) with widths up to 5 cm, the flame reached a steady state length, which demonstrates that flame length may be stabilized even when the edge effects are reduced. For the thick PMMA plates, flames reached lengths up to 70 cm but were highly energetic and restricted by oxygen depletion. Tests with the Nomex fabric confirmed that the cyclic flame phenomena, observed in small facility tests, continued over longer sample. New features were also observed at the higher oxygen/pressure conditions available in the large chamber. Comparison of flame behavior between the two facilities under identical conditions revealed disparities, both qualitative and quantitative. This suggests that, in certain ranges of controlling parameters, chamber size and shape could be one of the parameters that affect the material flammability. If this proves to be true, it may limit the applicability of existing flammability data.

Kleinhenz, Julie; Yuan, Zeng-Guang

2011-01-01

307

A microwave-transparent operant chamber for rats.  

PubMed

To study the operant behavior of rats in a microwave field, an operant chamber equipped with a response lever, stimulus lights, and a feeder was constructed using polycarbonate and fiber optic material. The chamber was connected to a personal computer located outside of the microwave chamber to program the schedules of reinforcement and to collect data. The operant chamber did not interfere with the microwave field and kept the subject's body parallel to the E-field for maximum absorption. PMID:1523241

Akyel, Y; Belt, M

1992-03-01

308

Flow characteristics of the dynamic "EPA flux chamber"  

Technology Transfer Automated Retrieval System (TEKTRAN)

A dynamic flux chamber, commonly referred as the “EPA chamber”, is one method that has been adapted to investigate spatial gas emission on feedlot surfaces. However, the flow characteristics within the chamber have not been evaluated to determine if it can be effectively used outside of its origina...

309

Engineering analyses of large precision cathode strip chambers for GEM  

SciTech Connect

Structural analyses of large precision cathode strip chambers performed up to the date of this publication are documented. Mechanical property data for typical chamber materials are included. This information, originally intended to be an appendix to the {open_quotes}CSC Structural Design Bible,{close_quotes} is presented as a guide for future designers of large chambers.

Horvath, J.A.; Belser, F.C.; Pratuch, S.M.; Wuest, C.R. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Mitselmakher, G. [Superconducting Super Collider Lab., Dallas, TX (United States)] [Superconducting Super Collider Lab., Dallas, TX (United States); Gordeev, A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)] [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Johnson, C.V. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); [Superconducting Super Collider Lab., Dallas, TX (United States); Polychronakos, V.A. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States); Golutvin, I.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)] [Joint Institute for Nuclear Research, Dubna (Russian Federation)

1993-10-21

310

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, John F. Kennedy Space Center, Florida. Drawing 68-K-L-11213, NASA KSC, November, 1968. CHAMBER ?L? ELEVATION. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

311

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, John F. Kennedy Space Center, Florida. Drawing 68-K-L-11213, NASA KSC, November, 1968. CHAMBER ?R? ELEVATION. Sheet 4 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

312

Detail of interior of compressed air chamber showing top of ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail of interior of compressed air chamber showing top of working chamber and tie rods that strengthen the outer shell plates of the compression chamber. - Sub Marine Explorer, Located along the beach of Isla San Telmo, Pearl Islands, Isla San Telmo, Former Panama Canal Zone, CZ

313

Structure of divided combustion chamber for internal combustion engine  

Microsoft Academic Search

This patent describes a structure defining a divided combustion chamber of an internal combustion engine, comprising an upper ceramic member, and a lower ceramic member having a transfer passage which communicates with a main combustion chamber of the engine. The upper and lower ceramic members meet with each other at an interface to form divided combustion chamber such that it

Y. Ogawa; T. Ogasawara; S. Hanzawa

1987-01-01

314

Annual Chamber Healthcare Summit DATE: Friday, October 21  

E-print Network

Annual Chamber Healthcare Summit DATE: Friday, October 21 TIME: 7am registration/7:30am breakfast/8 your tickets today! The Chamber's Healthcare Legislative Committee and the Small Business Council join and The Chamber's Healthcare Legislative Committee at the Four Points Hotel (3400 Airport Road, Allentown, PA

Snyder, Larry

315

NASDA life science experiment facilities for ISS  

NASA Astrophysics Data System (ADS)

National Space Development Agency of Japan (NASDA) has been developing various experiment facilities to conduct space biology researches in KIBO (JEM). The Cell Biology Experiment Facility (CBEF) and the Clean Bench (CB) are installed into JEM Life Science Rack. The Biological Experiment Units (BEU) are operated in the CBEF and the CB for many kinds of experiments on cells, tissues, plants, microorganisms, or small animals. It is possible for all researchers to use these facilities under the system of the International Announcement of Opportunity. The CBEF is a CO2 incubator to provide a controlled environment (temperature, humidity, and CO2 concentration), in which a rotating table is equipped to make variable gravity (0-2g) for reference experiments. The containers called "Canisters" can be used to install the BEU in the CBEF. The CBEF supplies power, command, sensor, and video interfaces for the BEU through the utility connectors of Canisters. The BEU is a multiuser system consisting of chambers and control segments. It is operated by pre-set programs and by commands from the ground. NASDA is currently developing three types of the BEU: the Plant Experiment Unit (PEU) for plant life cycle observations and the Cell Experiment Unit (CEU1&2) for cell culture experiments. The PEU has an automated watering system with a water sensor, an LED matrix as a light source, and a CCD camera to observe the plant growth. The CEUs have culture chambers and an automated cultural medium exchange system. Engineering models of the PEU and CEU1 have been accomplished. The preliminary design of CEU2 is in progress. The design of the BEU will be modified to meet science requirements of each experiment. The CB provides a closed aseptic work-space (Operation Chamber) with gloves for experiment operations. Samples and the BEU can be manually handled in the CB. The CB has an air lock (Disinfection Chamber) to prevent contamination, and HEPA filters to make class-100-equivalent clean air inside the Operation Chamber. Alcohol swabs and built-in ultraviolet lamps are used to sterilize instruments and insides of the CB. The phase contrast / fluorescent microscope is equipped in the Operation Chamber to support experiments. The observed image is monitored either on the CB LCD display or on the ground through a video downlink channel. Researchers on the ground can also operate the microscope with its remote control function. Flight models of the CBEF and the CB are scheduled for completion in 2002.

Tanigaki, F.; Masuda, D.; Yano, S.; Fujimoto, N.; Kamigaichi, S.

316

Considerations on neutron\\/environment characteristics in inertial fusion ignition (NIF) and reactor (KOYO) facilities  

Microsoft Academic Search

This paper reviews reported calculations on the assessment of some environmental questions related to neutron activation in ignition (National Ignition Facility, NIF) and reactor (KOYO Project) inertial fusion facilities. NIF results on the availability of the target chamber after different gain shots, inventories of activated gases in the bay area, and comments on radiological impacts from normal operations have shown

J. M Perlado

1999-01-01

317

Herds of methane chambers grazing bubbles  

NASA Astrophysics Data System (ADS)

Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique, localised bubbling zones on the water storage were found to produce over 50,000 mg m-2 d-1 and the areal extent ranged from 1.8 to 7% of the total reservoir area. The drivers behind these changes as well as lessons learnt from the system implementation are presented. This system exploits relatively cheap materials, sensing and computing and can be applied to a wide variety of aquatic and terrestrial systems.

Grinham, Alistair; Dunbabin, Matthew

2014-05-01

318

Replenishment of magma chambers by light inputs  

NASA Astrophysics Data System (ADS)

Magma chambers, particularly those of basaltic composition, are often replenished by an influx of magma whose density is less than that of the resident magma. This paper describes the fundamental fluid mechanics involved in the replenishment by light inputs. If ? denotes the uniform density of the resident magma and ? — ?? that of the input, the situation is described by the reduced gravity g' = g??/?, the volume flux Q, and the viscosities of the resident and input magmas ?e and ?i, respectively. The (nondimensional) Reynolds numbers, Ree = (g'Q3)1/5/?e and Rei = (g'Q3)1/5/?i and chamber geometry then completely specify the system. For sufficiently low values of the two Reynolds numbers (each less than approximately 10), the input rises as a laminar conduit. For larger values of the Reynolds numbers, the conduit may break down and exhibit either a varicose or a meander instability and entrain some resident magma. At still larger Reynolds numbers, the flow will become quite unsteady and finally turbulent. The values of the Reynolds numbers at which these transitions occur have been documented by a series of experiments with water, glycerine, and corn syrup. If the input rises as a turbulent plume, significant entrainment of the resident magma can take place. The final spatial distribution of the mixed magma depends on the geometry of the chamber. If the chamber is much wider than it is high, the mixed magma forms a compositionally stratified region between the roof and a sharp front above uncontaminated magma. In the other geometrical extreme, the input magma is mixed with almost all of the resident magma. If the density of the resident magma is already stratified, the input plume may penetrate only part way into the chamber, even though its initial density is less than that of the lowest density resident magma. The plume will then intrude horizontally and form a hybrid layer at an intermediate depth. This provides a mechanism for preventing even primitive basaltic magmas of minimum density from erupting at the surface. By conducting an experiment using aqueous solutions, we show that entrainment can lead to crystallization of the magma in the input plume by making it locally supersaturated. All these effects are discussed and illustrated by photographs of laboratory experiments.

Huppert, Herbert E.; Sparks, R. Stephen J.; Whitehead, John A.; Hallworth, Mark A.

1986-05-01

319

A combination drift chamber/pad chamber for very high readout rates  

SciTech Connect

Six medium-sized ({approx}1 {times} 2 m{sup 2}) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers.

Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W. (Fermi National Accelerator Lab., Batavia, IL (United States)); Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J. (Wisconsin Univ., Madison, WI (United States)); Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P. (Pavia Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Rome (Italy)); Arenton, M.; Conetti, S.

1991-11-01

320

Facility produced charge-exchange ions  

NASA Technical Reports Server (NTRS)

These facility produced ions are created by charge-exchange collisions between neutral atoms and energetic thruster beam ions. The result of the electron transfer is an energetic neutral atom and an ion of only thermal energy. There are true charge-exchange ions produced by collisions with neutrals escaping from the ion thruster and being charge-exchange ionized before the neutral intercepts the tank wall. The facility produced charge-exchange ions will not exist in space and therefore, represent a source of error where measurements involving ion thruster plasmas and their density are involved. The quantity of facility produced ions in a test chamber with a 30 cm mercury ion thruster was determined.

Carruth, M. R., Jr.

1981-01-01

321

Calculation of pulsed kicker magnetic field attenuation inside beam chambers.  

SciTech Connect

The ceramic beam chambers in the sections of the kicker magnets for the beam injection and extraction in the Advanced Photon Source (APS) are made of alumina. The inner surface of the ceramic chamber is coated with a conductive paste. The choice of coating thickness is intended to reduce the shielding of the pulsed kicker magnetic field while containing the electromagnetic fields due to the beam bunches inside the chamber, and minimize the Ohmic heating due to the fields on the chamber [1]. The thin coating generally does not give a uniform surface resistivity for typical dimensions of the ceramic chambers in use. The chamber cross section is a circular or an elliptic shape. The chamber or its wall thickness refers to the conductive coating in the following sections. This note calculates the penetration of the kicker magnetic field inside the beam chamber. The kicker field is assumed to be a half-sine pulse and be spatially uniform over the chamber dimensions. The purpose of the calculation is to be able to deduce the average surface resistivity of a chamber by fitting the measured magnetic field data with the calculation inside the chamber. In the following section, assuming that the coating thickness d is much smaller than the classical skin depth {delta}, the penetrated field inside the chamber is calculated by subtracting the shielding field due to the eddy currents. In Section 3, for the kicker fields parallel and perpendicular to the axis of a circular beam chamber, the fields inside the chamber with an arbitrary wall thickness are calculated. For both directions of the kicker fields, the approximations made for d << {delta} achieve the same results as given in Section 2. For elliptic chambers, the calculations for the vector potentials are not completed because of the tedious approximation procedure with Mathieu functions. Instead, the results in Section 2 and the time constants calculated for the elliptic geometries in Table 1 could be used for the purpose of this note.

Kim, S. H.

2001-04-06

322

A Freon-filled bubble chamber for neutron detection in inertial confinement fusion experiments.  

PubMed

Neutron imaging is one of the main methods used in inertial confinement fusion experiments to measure the core symmetry of target implosions. Previous studies have shown that bubble chambers have the potential to obtain higher resolution images of the targets for a shorter source-to-target distance than typical scintillator arrays. A bubble chamber for neutron imaging with Freon 115 as the active medium was designed and built for the OMEGA laser system. Bubbles resulting from spontaneous nucleation were recorded. Bubbles resulting from neutron-Freon interactions were observed at neutron yields of 10(13) emitted from deuterium-tritium target implosions on OMEGA. The measured column bubble density was too low for neutron imaging on OMEGA but agreed with the model of bubble formation. The recorded data suggest that neutron bubble detectors are a promising technology for the higher neutron yields expected at National Ignition Facility. PMID:21456730

Ghilea, M C; Meyerhofer, D D; Sangster, T C

2011-03-01

323

Solar Thermal Propulsion Test Facility  

NASA Technical Reports Server (NTRS)

Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. This photograph shows a fully assembled solar thermal engine placed inside the vacuum chamber at the test facility prior to testing. The 20- by 24-ft heliostat mirror (not shown in this photograph) has a dual-axis control that keeps a reflection of the sunlight on the 18-ft diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move theNation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth orbit, rapid travel throughout the solar system, and exploration of interstellar space.

1999-01-01

324

Solar Thermal Propulsion Test Facility  

NASA Technical Reports Server (NTRS)

Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. This photograph, taken at MSFC's Solar Thermal Propulsion Test Facility, shows a concentrator mirror, a combination of 144 mirrors forming this 18-ft diameter concentrator, and a vacuum chamber that houses the focal point. The 20- by 24-ft heliostat mirror (not shown in this photograph) has a dual-axis control that keeps a reflection of the sunlight on the 18-foot diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move the Nation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth-orbit, rapid travel throughout the solar system, and exploration of interstellar space.

1999-01-01

325

Breadboard Facility  

NASA Technical Reports Server (NTRS)

In the sixties, Chrysler was NASA's prime contractor for the Saturn I and IB test launch vehicles. The company installed and operated at Huntsville what was known as the Saturn I/IB Development Breadboard Facility. "Breadboard," means an array of electrical and electronic equipment for performing a variety of development and test functions. This work gave Chrysler a broad capability in computerized testing to assure quality control in development of solid-state electronic systems. Today that division is manufacturing many products not destined for NASA, most of them being associated with the company's automotive line. A major project is production and quality-control testing of the "lean-burn" engine, one that has a built-in Computer to control emission timing, and allow the engine to run on a leaner mixture of fuel and air. Other environment-related products include vehicle emission analyzers. The newest of the line is an accurate, portable solid state instrument for testing auto exhaust gases. The exhaust analyzers, now being produced for company dealers and for service

1977-01-01

326

Some effects of cyclic induced deformation in rocket thrust chambers  

NASA Technical Reports Server (NTRS)

A test program to investigate the deformation process observed in the hot gas wall of rocket thrust chambers was conducted using three different liner materials. Five thrust chambers were cycled to failure using hydrogen and oxygen as propellants at a chamber pressure of 4.14 MN/sq m. The deformation was observed nondestructively at midlife points and destructively after failure occurred. The cyclic life results are presented with an accompanying discussion about the types of failure encountered. Data indicating the deformation of the thrust chamber liner as cycles are accumulated are presented for each of the test thrust chambers.

Hannum, N. P.; Quentmeyer, R. J.; Kasper, H. J.

1979-01-01

327

Theoretical Performance of Hydrogen-Oxygen Rocket Thrust Chambers  

NASA Technical Reports Server (NTRS)

Data are presented for liquid-hydrogen-liquid-oxygen thrust chambers at chamber pressures from 15 to 1200 pounds per square inch absolute, area ratios to approximately 300, and percent fuel from about 8 to 34 for both equilibrium and frozen composition during expansion. Specific impulse in vacuum, specific impulse, combustion-chamber temperature, nozzle-exit temperature, characteristic velocity, and the ratio of chamber-to-nozzle-exit pressure are included. The data are presented in convenient graphical forms to allow quick calculation of theoretical nozzle performance with over- or underexpansion, flow separation, and introduction of the propellants at various initial conditions or heat loss from the combustion chamber.

Sievers, Gilbert K.; Tomazic, William A.; Kinney, George R.

1961-01-01

328

Study on optimization of multiionization-chamber system for BNCT.  

PubMed

In order to monitor stability of doses from the four components such as thermal, epi-thermal, fast neutron and gamma-ray during BNCT irradiation, we are developing a multiionization-chamber system. This system is consisted of four kinds of ionization chamber, which have specific sensitivity for each component, respectively. Since a suitable structure for each chamber depends on the energy spectrum of the irradiation field, the optimization study of the chamber structures for the epi-thermal neutron beam of cyclotron-based epi-thermal neutron source (C-BENS) was performed by using a Monte Carlo simulation code "PHITS" and suitable chamber-structures were determined. PMID:21463949

Fujii, T; Tanaka, H; Maruhashi, A; Ono, K; Sakurai, Y

2011-12-01

329

Vacuum chamber with a supersonic flow aerodynamic window  

DOEpatents

A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Hanson, Clark L. (Livermore, CA)

1982-01-01

330

Vacuum chamber with a supersonic-flow aerodynamic window  

DOEpatents

A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Hanson, C.L.

1980-10-14

331

Energy Systems Test Area (ESTA). Power Systems Test Facilities  

NASA Technical Reports Server (NTRS)

This viewgraph presentation provides a detailed description of the Johnson Space Center's Power Systems Facility located in the Energy Systems Test Area (ESTA). Facilities and the resources used to support power and battery systems testing are also shown. The contents include: 1) Power Testing; 2) Power Test Equipment Capabilities Summary; 3) Source/Load; 4) Battery Facilities; 5) Battery Test Equipment Capabilities Summary; 6) Battery Testing; 7) Performance Test Equipment; 8) Battery Test Environments; 9) Battery Abuse Chambers; 10) Battery Abuse Capabilities; and 11) Battery Test Area Resources.

Situ, Cindy H.

2010-01-01

332

High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines  

NASA Technical Reports Server (NTRS)

Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion chamber liner. Properties of optimized NARloy-Z-D composite material will also be presented.

Bhat, Biliyar N.; Ellis, David; Singh, Jogender

2014-01-01

333

NASA Glenn Research Center Creek Road Complex—Cryogenic Testing Facilities  

NASA Astrophysics Data System (ADS)

Due to expansion at neighboring Cleveland Hopkins Airport, several NASA Glenn Research Center (GRC) facilities have been relocated to the Creek Road Complex. The complex consists of the Small Scale Multi-purpose Research Facility (SMiRF), Cryogenic Components Lab Cell 7 (CCL-7), and a shop building. The facilities have been updated and include state-of-the art technology. SMiRF is a liquid hydrogen/liquid nitrogen (LH 2/LN 2) test facility used to conduct research in a 7400 L vacuum chamber. The chamber simulates space environment and launch vehicle ascent profile. SMiRF handles 5680 L of LH 2. CCL is a LH 2/LN 2 facility to perform small scale proof of concept tests for components and processes. It handles 1130 L of liquid hydrogen. Both facilities handle cryogens at sub-atmospheric pressures.

Jurns, John M.; Kudlac, Maureen T.

2006-02-01

334

Vacuum chamber for containing particle beams  

DOEpatents

A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.

Harvey, A.

1985-11-26

335

Ion feedback suppression in time projection chambers  

NASA Astrophysics Data System (ADS)

A controlled-voltage Gas Electron Multiplier (GEM) can be used to block the re-injection of positive ions in large volume Time Projection Chambers (TPC). With proper choice of geometry, gas filling and external fields, good electron transmission can be obtained at very low GEM voltages; pulsed ion gating is then much easier than with conventional wire grids, requiring hundreds of volts. Gating schemes suited for the TPC detector planned for the International Linear Collider detector are described. The possibility of GEM-based DC-operated ion filters, exploiting the difference in diffusion properties of ions and electrons, is also discussed.

Sauli, F.; Ropelewski, L.; Everaerts, P.

2006-05-01

336

The time projection chamber at triumf  

NASA Astrophysics Data System (ADS)

The time projection chamber at TRIUMF is being used to search for muon-electron conversion. The best spatial resolution in the TPC, ??200 ?m, occurs at the minimum drift length and for an optimum track-to-anode crossing angle determined by the magnetic field. The observed resolution is dependent on th diffusion of the drifting electrons, the track-to-anode crossing angle, E?×B? effects near the anode wire and the discrete nature of the ionization process. Distortions due to positive ions leaking back into the drift volume from the anode wire region have been nearly eliminated by the use of a pulsed dual grid system.

Bryman, D.; Leitch, M.; Navon, I.; Numao, T.; Schlatter, P.; Dixit, M. S.; Hargrove, C. K.; Mes, H.; Bennett, A.; Macdonald, J. A.; Skegg, R.; Spuller, J.; Burnham, A.; Hasinoff, M.; Poutissou, J.-M.; Azuelos, G.; Depommier, P.; Martin, J.-P.; Poutissou, R.; Blecher, M.; Gotow, K.; Carter, A. L.

1984-02-01

337

Sensing circuits for multiwire proportional chambers  

NASA Technical Reports Server (NTRS)

Integrated sensing circuits were designed, fabricated, and packaged for use in determining the direction and fluence of ionizing radiation passing through a multiwire proportional chamber. CMOS on sapphire was selected because of its high speed and low power capabilities. The design of the proposed circuits is described and the results of computer simulations are presented. The fabrication processes for the CMOS on sapphire sensing circuits and hybrid substrates are outlined. Several design options are described and the cost implications of each discussed. To be most effective, each chip should handle not more than 32 inputs, and should be mounted on its own hybrid substrate.

Peterson, H. T.; Worley, E. R.

1977-01-01

338

Review of isothermal haze chamber performance  

NASA Technical Reports Server (NTRS)

The theory of this method of characterizing cloud condensation nuclei (CCN) over the critical supersaturation range of about 0.01% to 0.2% was reviewed, and guidelines for the design and operation of IHC's are given. IHC data are presented and critically analyzed. Two of the four IHC's agree to about 40% over the entire range of critical. a third chamber shows similar agreement with the first two over the lower part of the critical supersaturation range but only a factor of two agreement at higher supersaturation. Some reasons for the discrepancies are given.

Fitzgerald, J. W.; Rogers, C. F.; Hudson, J. G.

1981-01-01

339

Vacuum chamber for containing particle beams  

DOEpatents

A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer, such as nickel can be coated on the inside of the pipe.

Harvey, Alexander (Los Alamos, NM)

1987-01-01

340

Target alignment in the National Ignition Facility  

SciTech Connect

Accurate placement of hundreds of focused laser beams on target is necessary to achieve success in the National Ignition Facility (NIF). The current system requirement is {le}7 {mu}rad error in output pointing and {le}1 mm error in focusing. To accommodate several system shots per day, a target alignment system must be able to align the target to chamber center, inject an alignment beam to represent each shot beam, and point and focus the alignment beams onto the target in about one hour. At Lawrence Livermore National Laboratory, we have developed a target alignment concept and built a prototype to validate the approach. The concept comprises three systems: the chamber center reference, target alignment sensor, and target alignment beams.

Vann, C.S.; Bliss, E.S.; Murray, J.E.

1994-06-06

341

Facility Focus: Sports and Recreation Facilities.  

ERIC Educational Resources Information Center

Examines projects that demonstrate three different commitments administrators make to their athletic facilities: convenience; excellence; and comfort. Projects discussed involve a fitness center, a football stadium, and a multi-sport indoor practice facility. (GR)

College Planning & Management, 2000

2000-01-01

342

Design and characterization of a smog chamber for studying gas-phase chemical mechanisms and aerosol chemistry  

NASA Astrophysics Data System (ADS)

We describe here characterization of a new state-of-the-art smog chamber facility for studying atmospheric gas phase and aerosol chemistry. The chamber consists of a 30 m3 fluorinated ethylene propylene (FEP) Teflon film reactor suspended in a temperature-controlled enclosure equipped with two banks of black lamps as the light source. Temperature can be set in the range from -10 °C to 40 °C at accuracy of ±1 °C as measured by eight temperature sensors inside the enclosure and one just inside the reactor. Matrix air can be purified with NMHCs < 0.5 ppb, NOx/O3/carbonyls < 1 ppb and particles < 1 cmchamber are determined and included in the Master Chemical Mechanism to evaluate and model propene-NOx-air irradiation experiments. The results indicate that this new smog chamber can provide high quality data for mechanism evaluation. Results of ?-pinene dark ozonolysis experiments revealed SOA yields comparable to those from other chamber studies, and the two-product model gives a good fit for the yield data obtained in this work. Characterization experiments demonstrate that our GIG-CAS smog chamber facility can be used to provide valuable data for gas-phase mechanisms and aerosol chemistry.

Wang, X.; Liu, T.; Bernard, F.; Ding, X.; Wen, S.; Zhang, Y.; Zhang, Z.; He, Q.; Lü, S.; Chen, J.; Saunders, S.; Yu, J.

2013-08-01

343

Design and characterization of a smog chamber for studying gas-phase chemical mechanisms and aerosol formation  

NASA Astrophysics Data System (ADS)

We describe here characterization of a new state-of-the-art smog chamber facility for studying atmospheric gas-phase and aerosol chemistry. The chamber consists of a 30 m3 fluorinated ethylene propylene (FEP) Teflon film reactor housed in a temperature-controlled enclosure equipped with black lamps as the light source. Temperature can be set in the range from -10 to 40 °C at accuracy of ±1 °C as measured by eight temperature sensors inside the enclosure and one just inside the reactor. Matrix air can be purified with non-methane hydrocarbons (NMHCs) < 0.5 ppb, NOx/O3/carbonyls < 1 ppb and particles < 1 cm-3. The photolysis rate of NO2 is adjustable between 0 and 0.49 min-1. At 298 K under dry conditions, the average wall loss rates of NO, NO2 and O3 were measured to be 1.41 × 10-4 min-1, 1.39 × 10-4 min-1 and 1.31 × 10-4 min-1, respectively, and the particle number wall loss rate was measured to be 0.17 h-1. Auxiliary mechanisms of this chamber are determined and included in the Master Chemical Mechanism to evaluate and model propene-NOx-air irradiation experiments. The results indicate that this new smog chamber can provide high-quality data for mechanism evaluation. Results of ?-pinene dark ozonolysis experiments revealed secondary organic aerosol (SOA) yields comparable to those from other chamber studies, and the two-product model gives a good fit for the yield data obtained in this work. Characterization experiments demonstrate that our Guangzhou Institute of Geochemistry, Chinese Academy Sciences (GIG-CAS), smog chamber facility can be used to provide valuable data for gas-phase chemistry and secondary aerosol formation.

Wang, X.; Liu, T.; Bernard, F.; Ding, X.; Wen, S.; Zhang, Y.; Zhang, Z.; He, Q.; Lü, S.; Chen, J.; Saunders, S.; Yu, J.

2014-01-01

344

ECR Based Low Energy Ion Beam Facility at VECC, Kolkata  

NASA Astrophysics Data System (ADS)

A low energy heavy ion irradiation/implantation facility has been developed at VECC, Kolkata for materials science and atomic physics research, utilizing indigenously developed 6.4 GHz ECR ion source. The facility provides high charge state ion beams of N, O, Ne, Ar, S, Kr, Xe, Fe, Ti, Hf etc. up to a few micro amperes to an energy of 10 keV per charge state.The beam energy can be further enhanced by floating the target at a negative potential (up to 25 kV). The ion beam is focused to a spot of about 2 mm diameter on the target using a set of glaser lenses. A x-y scanner is used to scan the beam over a target area of 10 mm x 10 mm to obtain uniform implantation. The recently commissioned multi facility sample chamber has provision for mounting multiple samples on indigenously developed disposable beam viewers for insitu beam viewing during implantation. The ionization chamber of ECR source is mainly pumped by ECR plasma. An additional pumping speed has been provided through extraction hole and pumping slots to obtain low base pressure. In the ion source, base pressure of 1x10-7 Torr in injector stage and ~5x10-8 Torr in extraction chamber have been routinely obtained. The ultra-high vacuum multi facility experimental chamber is generally kept at ~ 1x10-7 Torr during implantation on the targets. This facility is a unique tool for studying fundamental and technologically important problems of materials science and atomic physics research. High ion flux available from this machine is suitable for generating high defect densities i.e. high value of displacement-per-atom (dpa). Recently this facility has been used for studies like "Tunability of dielectric constant of conducting polymer Polyaniline (PANI) by low energy Ar9+ irradiation" and "Fe10+ implantation in ZnO for synthesis of dilute magnetic semiconductor".

Taki, G. S.; Chakraborty, D. K.; Ghosh, Subhash; Majhi, S.; Pal, Gautam; Mallik, C.; Bhandari, R. K.; Krishna, J. B. M.; Dey, K.; Sinha, A. K.

2012-11-01

345

R2 REGULATED FACILITIES  

EPA Science Inventory

The Facility Registry System (FRS) is a centrally managed database that identifies facilities, sites or places subject to environmental regulations or of environmental interest. FRS creates high-quality, accurate, and authoritative facility identification records through rigorous...

346

Nursing Facilities (Medicaid)  

MedlinePLUS

Nursing Facilities (NF) Nursing Facility Services are provided by Medicaid certified nursing homes, which primarily provide three ... provided by Medicaid or other state agencies. Where Nursing Facility Services are provided Medicaid coverage of Nursing ...

347

Wire chamber radiation detector with discharge control  

DOEpatents

A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

Perez-Mendez, Victor (Berkeley, CA); Mulera, Terrence A. (Berkeley, CA)

1984-01-01

348

Rocket thrust chamber thermal barrier coatings  

NASA Technical Reports Server (NTRS)

A research program was conducted to generate data and develop analytical techniques to predict the performance and reliability of ceramic thermal barrier coatings in high heat flux environments. A finite element model was used to analyze the thermomechanical behavior of coating systems in rocket thrust chambers. Candidate coating systems (using a copper substrate, NiCrAlY bond coat and ZrO2.8Y2O3 ceramic overcoat) were selected for detailed study based on photomicrographic evaluations of experimental test specimens. The effects of plasma spray application parameters on the material properties of these coatings were measured and the effects on coating performance evaluated using the finite element model. Coating design curves which define acceptable operating envelopes for seleted coating systems were constructed based on temperature and strain limitations. Spray gun power levels was found to have the most significant effect on coating structure. Three coating systems were selected for study using different power levels. Thermal conductivity, strain tolerance, density, and residual stress were measured for these coatings. Analyses indicated that extremely thin coatings ( 0.02 mm) are required to accommodate the high heat flux of a rocket thrust chamber and ensure structural integrity.

Batakis, A. P.; Vogan, J. W.

1985-01-01

349

Development of Large Area GEM Chambers  

NASA Astrophysics Data System (ADS)

The High Energy Physics group of the University of Texas at Arlington Physics Department has been developing Gas Electron Multiplier (GEM) detectors for use as the sensitive gap detector in digital hadron calorimeters (DHCAL) for the future International Linear Collider. In this study, two kinds of prototype GEM detectors have been tested. One has 30x30 cm2 active area double GEM structure with a 3 mm drift gap, a 1 mm transfer gap and a 1 mm induction gap. The other one has two 2x2 cm2 GEM foils in the amplifier stage with a 5 mm drift gap, a 2 mm transfer gap and a 1 mm induction gap. We present characteristics of these detectors obtained using high-energy charged particles, cosmic ray muons and 106Ru and 55Fe radioactive sources. From the 55Fe tests, we observed two well-separated X-ray emission peaks and measured the chamber gain to be over 6500 with a high voltage of 395 V across each GEM electrode. Both the spectra from cosmic rays and the 106Ru fit well to Landau distributions as expected from minimum ionizing particles. We also present the chamber performance after high dosage exposure to radiation as well as the pressure dependence of the gain and correction factors. Finally, we discuss the quality test results of the first set of large scale GEM foils and discuss progress and future plans for constructing large scale (100cmx100 cm) GEM detectors.

Yu, J.; Baldelomar, E.; Park, K.; Park, S.; Sosebee, M.; Tran, N.; White, A. P.

350

Accumulation of spatial charge in the time projection chamber of a multipurpose detector  

NASA Astrophysics Data System (ADS)

This article presents the results of a numerical simulation of the process of spatial positive charge accumulation in the Time Projection Chamber (TPC) of the multipurpose detector (MPD) at Nuclotron-based Ion Collider fAcility (NICA) at the Joint Institute for Nuclear Research (JINR). Based on the spatial distribution of the charges, the problem of calculating the potential of the electrostatic field created by these charges has been solved. The radial, angular, and axial distortions in the electron motions from the point of ionization to the readout planes are calculated.

Merts, S. P.; Razin, S. V.; Rogachevskii, O. V.

2013-01-01

351

A new multi-strip ionization chamber used as online beam monitor for heavy ion therapy  

NASA Astrophysics Data System (ADS)

A multi-strip ionization chamber has been built for precise and fast monitoring of the carbon beam spatial distribution at Heavy Ion Researched Facility of Lanzhou Cooling Storing Ring (HIRFL-CSR). All the detector's anode, cathode and sealed windows are made by 2 ?m aluminized Mylar film in order to minimize the beam lateral deflection. The sensitive area of the detector is (100×100) mm2, with the anode segmented in 100 strips, and specialized front-end electronics has been developed for simplifying the data acquisition and quick feedback of the relevant parameters to beam control system. It can complete one single beam profile in 200 ?s.

Xu, Zhiguo; Mao, Ruishi; Duan, Limin; She, Qianshun; Hu, Zhengguo; Li, He; Lu, Ziwei; Zhao, Qiecheng; Yang, Herun; Su, Hong; Lu, Chengui; Hu, Rongjiang; Zhang, Junwei

2013-11-01

352

Space shuttle orbit maneuvering engine reusable thrust chamber: Adverse operating conditions test report  

NASA Technical Reports Server (NTRS)

Test hardware, facilities, and procedures are described along with results of electrically heated tube and channel tests conducted to determine adverse operating condition limits for convectively cooled chambers typical of Space Shuttle Orbit Manuevering Engine designs. Hot-start tests were conducted with corrosion resistant steel and nickel tubes with both monomethylhydrazine and 50-50 coolants. Helium ingestion, in both bubble and froth form, was studied in tubular test sections. Helium bubble ingestion and burn-out limits in rectangular channels were also investigated.

Tobin, R. D.

1974-01-01

353

Design Study Conducted of a Stirred and Perfused Specimen Chamber for Culturing Suspended Cells on the International Space Station  

NASA Technical Reports Server (NTRS)

A tightly knit numerical/experimental collaboration among the NASA Ames Research Center, NASA Glenn Research Center, and Payload Systems, Inc., was formed to analyze cell culturing systems for the International Space Station. The Cell Culture Unit is a facility scheduled for deployment on the space station by the Cell Culture Unit team at Ames. The facility houses multiple cell specimen chambers (CSCs), all of which have inlets and outlets to allow for replenishment of nutrients and for waste removal. For improved uniformity of nutrient and waste concentrations, each chamber has a pair of counterrotating stir bars as well. Although the CSC can be used to grow a wide variety of organic cells, the current study uses yeast as a model cell. Previous work identified groundbased protocols for perfusion and stirring to achieve yeast growth within the CSC that is comparable to that for yeast cultures grown in a shaken Ehrlenmeyer flask.

Nelson, Emily S.; Kizito, John P.

2003-01-01

354

Lewis Research Center R and D Facilities  

NASA Technical Reports Server (NTRS)

The NASA Lewis Research Center (LeRC) defines and develops advanced technology for high priority national needs. The work of the Center is directed toward new propulsion, power, and communications technologies for application to aeronautics and space, so that U.S. leadership in these areas is ensured. The end product is knowledge, usually in a report, that is made fully available to potential users--the aircraft engine industry, the energy industry, the automotive industry, the space industry, and other NASA centers. In addition to offices and laboratories for almost every kind of physical research in such fields as fluid mechanics, physics, materials, fuels, combustion, thermodynamics, lubrication, heat transfer, and electronics, LeRC has a variety of engineering test cells for experiments with components such as compressors, pumps, conductors, turbines, nozzles, and controls. A number of large facilities can simulate the operating environment for a complete system: altitude chambers for aircraft engines; large supersonic wind tunnels for advanced airframes and propulsion systems; space simulation chambers for electric rockets or spacecraft; and a 420-foot-deep zero-gravity facility for microgravity experiments. Some problems are amenable to detection and solution only in the complete system and at essentially full scale. By combining basic research in pertinent disciplines and generic technologies with applied research on components and complete systems, LeRC has become one of the most productive centers in its field in the world. This brochure describes a number of the facilities that provide LeRC with its exceptional capabilities.

1991-01-01

355

Two-dimensional ionization chamber arrays for IMRT plan verification  

SciTech Connect

In this paper we describe a concept for dosimetric treatment plan verification using two-dimensional ionization chamber arrays. Two different versions of the 2D-ARRAY (PTW-Freiburg, Germany) will be presented, a matrix of 16x16 chambers (chamber cross section 8 mmx8 mm; the distance between chamber centers, 16 mm) and a matrix of 27x27 chambers (chamber cross section 5 mmx5 mm; the distance between chamber centers is 10 mm). The two-dimensional response function of a single chamber is experimentally determined by scanning it with a slit beam. For dosimetric plan verification, the expected two-dimensional distribution of the array signals is calculated via convolution of the planned dose distribution, obtained from the treatment planning system, with the two-dimensional response function of a single chamber. By comparing the measured two-dimensional distribution of the array signals with the expected one, a distribution of deviations is obtained that can be subjected to verification criteria, such as the gamma index criterion. As an example, this verification method is discussed for one sequence of an IMRT plan. The error detection capability is demonstrated in a case study. Both versions of two-dimensional ionization chamber arrays, together with the developed treatment plan verification strategy, have been found to provide a suitable and easy-to-handle quality assurance instrument for IMRT.

Poppe, Bjoern; Blechschmidt, Arne; Djouguela, Armand; Kollhoff, Ralf; Rubach, Antje; Willborn, Kay C.; Harder, Dietrich [Klinik fuer Strahlentherapie und Internistische Onkologie, Pius-Hospital, Oldenburg, Germany, and Carl-von-Ossietzky-Universitaet Oldenburg, Oldenburg (Germany); Carl-von-Ossietzky-Universitaet Oldenburg, Oldenburg (Germany); Klinik fuer Strahlentherapie und Internistische Onkologie, Pius-Hospital, Oldenburg (Germany); Georg-August-Universitaet Goettingen, Goettingen (Germany)

2006-04-15

356

Transpiring Cooling of a Scram-Jet Engine Combustion Chamber  

NASA Technical Reports Server (NTRS)

The peak cold-wall heating rate generated in a combustion chamber of a scram-jet engine can exceed 2000 Btu/sq ft sec (approx. 2344 W/sq cm). Therefore, a very effective heat dissipation mechanism is required to sustain such a high heating load. This research focused on the transpiration cooling mechanism that appears to be a promising approach to remove a large amount of heat from the engine wall. The transpiration cooling mechanism has two aspects. First, initial computations suggest that there is a reduction, as much as 75%, in the heat flux incident on the combustion chamber wall due to the transpirant modifying the combustor boundary layer. Secondly, the heat reaching the combustor wall is removed from the structure in a very effective manner by the transpirant. It is the second of these two mechanisms that is investigated experimentally in the subject paper. A transpiration cooling experiment using a radiant heating method, that provided a heat flux as high as 200 Btu/sq ft sec ( approx. 234 W/sq cm) on the surface of a specimen, was performed. The experiment utilized an arc-lamp facility (60-kW radiant power output) to provide a uniform heat flux to a test specimen. For safety reasons, helium gas was used as the transpirant in the experiments. The specimens were 1.9-cm diameter sintered, powdered-stainless-steel tubes of various porosities and a 2.54cm square tube with perforated multi-layered walls. A 15-cm portion of each specimen was heated. The cooling effectivenes and efficiencies by transpiration for each specimen were obtained using the experimental results. During the testing, various test specimens displayed a choking phenomenon in which the transpirant flow was limited as the heat flux was increased. The paper includes a preliminary analysis of the transpiration cooling mechanism and a scaling conversion study that translates the results from helium tests into the case when a hydrogen medium is used.

Choi, Sang H.; Scotti, Stephen J.; Song, Kyo D.; Ries,Heidi

1997-01-01

357

Guide to research facilities  

SciTech Connect

This Guide provides information on facilities at US Department of Energy (DOE) and other government laboratories that focus on research and development of energy efficiency and renewable energy technologies. These laboratories have opened these facilities to outside users within the scientific community to encourage cooperation between the laboratories and the private sector. The Guide features two types of facilities: designated user facilities and other research facilities. Designated user facilities are one-of-a-kind DOE facilities that are staffed by personnel with unparalleled expertise and that contain sophisticated equipment. Other research facilities are facilities at DOE and other government laboratories that provide sophisticated equipment, testing areas, or processes that may not be available at private facilities. Each facility listing includes the name and phone number of someone you can call for more information.

Not Available

1993-06-01

358

Preliminary studies of a new monitor ionization chamber.  

PubMed

A new monitor ionization chamber was developed at Instituto de Pesquisas Energéticas e Nucleares (IPEN) in order to monitor X-ray beams. The main difference of this monitor ionization chamber in relation to other monitor chambers is its geometry, which consists of a ring-shaped sensitive volume. Because of this geometry, the monitor chamber has a central hole through which the direct radiation beam passes. The operational characteristics of the monitor chamber were evaluated: saturation, ion collection efficiency and polarity effect. Besides these tests, the short- and medium-term stabilities of its response were also evaluated. During the tests the leakage current was always negligible. All results showed values within those recommended internationally (IEC, 1997. Medical electrical equipment-dosimeters with ionization chambers and/or semi-conductor detectors as used in X-ray diagnostic imaging. IEC 61674. International Electrotechnical Commission, Genève). PMID:19819153

Yoshizumi, Maíra T; Vivolo, Vitor; Caldas, Linda V E

2010-01-01

359

EFFECTS OF ACTIVATED CHARCOAL FILTRATION AND OZONATION ON HYDROCARBON AND CARBONYL LEVELS OF AMBIENT AIR USED IN CONTROLLED-EXPOSURE CHAMBER STUDIES OF AIR POLLUTANT HUMAN HEALTH EFFECTS  

EPA Science Inventory

Air sampling experiments were done in 1985, 1987, and 1993 at the human-exposure chamber facility of the U.S. EPA Health Effects Research Laboratory in Chapel Hill, NC. easurements of VOC's by GC-FID and aldehyde measurements by the DNPH silica gel cartridge method were made, com...

360

Molecular Contamination Investigation Facility (MCIF) Capabilities  

NASA Technical Reports Server (NTRS)

This facility was used to guide the development of ASTM E 1559 center dot Multiple Quartz Crystal Microbalances (QCMs), large sample and spectral effects capability center dot Several instrumented, high vacuum chamber systems are used to evaluate the molecular outgassing characteristics of materials, flight components and other sensitive surfaces. Test materials for spacecraft/instrument selection center.Test flight components for acceptable molecular outgas levels center dot Determine time/temperature vacuum bake-out requirements center. Data used to set limits for use of materials and specific components center. Provide Input Data to Contamination Transport Models -Applied to numerous flight projects over the past 20 years.

Soules, David M.

2013-01-01

361

Use of a whirling cup rotor to stir benthic chambers  

Microsoft Academic Search

Realistic stirring is an important concern when using benthic chambers to measure processes at the sediment-water column interface.\\u000a A simple whirling cup rotor device that is driven by external flow and stirs benthic chambers effectively is described here.\\u000a Flow tank studies and field studies demonstrated that this device homogenizes benthic chambers rapidly and responds quickly\\u000a and linearly to external flow

Lawrence B. Cahoon

1988-01-01

362

On a new method for testing and calibrating wire chambers  

NASA Astrophysics Data System (ADS)

The latent tracks caused by ionizing particles in wire chambers can be simulated by a pulsed laser beam, if molecules having appropriate ionization potential, absorption band structure and vapour pressure are admixed to the chamber gas. This can be used for chamber calibration. First tests [1] with N 2-laser light (337 nm) and Ni(C 5 H 5) 2, were extended to include several organic compounds using a pumped tunable dye laser (428-450 nm).

Anderhub, H.; Devereux, M.; Seiler, P. G.

1980-10-01

363

Tests of a Novel Design of Resistive Plate Chambers  

E-print Network

A novel design of Resistive Plate Chambers (RPCs), using only a single resistive plate, is being proposed. Based on this design, two large size prototype chambers were constructed and were tested with cosmic rays and in particle beams. The tests confirmed the viability of this new approach. In addition to showing an improved single-particle response compared to the traditional 2-plate design, the novel chambers also prove to be suitable for calorimetric applications.

Bilki, B; Freund, B; Neubüser, C; Onel, Y; Repond, J; Schlereth, J; Xia, L

2015-01-01

364

Technical Review of the Laboratory Biosphere Closed Ecological System Facility  

NASA Astrophysics Data System (ADS)

The "Laboratory Biosphere", a new closed ecological system facility in Santa Fe, New Mexico (USA) has been constructed and became operational in May 2002. Built and operated by the Global Ecotechnics consortium (Biosphere Technologies and Biosphere Foundation with Biospheric Design Inc., and the Institute of Ecotechnics), the research apparatus for intensive crop growth, biogeochemical cycle dynamics and recycling of inedible crop biomass comprises a sealed cylindrical steel chamber and attached variable volume chamber (lung) to prevent pressures caused by the expansion and contraction of the contained air. The cylindrical growing chamber is 3.7m (12 feet) long and 3.7m (12 foot) diameter, giving an internal volume of 34 m3 (1200 ft 3 ). The two crop growth beds cover 5.5 m2, with a soil depth of 0.3m (12 inches), with 12 x 1000 watt high-pressure sodium lights capable of variable lighting of 40-70 mol per m2 per day. A small soil bed reactor in the chamber can be activated to help with metabolism of chamber trace gases. The volume of the attached variable volume chamber (lung) can range between 0-11 m3 (0-400 ft 3 ). Evapotranspired and soil leachate water are collected, combined and recycled to water the planting beds. Sampling ports enable testing of water quality of leachate, condensate and irrigation water. Visual inspection windows provide views of the entire interior and growing beds. The chamber is also outfitted with an airlock to minimize air exchange when people enter and work in the chamber. Continuous sensors include atmospheric CO2 and oxygen, temperature, humidity, soil moisture, light level and water levels in reservoirs. Both "sniffer" (air ports) and "sipper" (water ports) will enable collection of water or air samples for detailed analysis. This paper reports on the development of this new soil-based bioregenerative life support closed system apparatus and its technical challenges and capabilities.

Dempster, W.; van Thillo, M.; Alling, A.; Allen, J.; Silverstone, S.; Nelson, M.

365

Nuclear Fission Investigation with Twin Ionization Chamber  

NASA Astrophysics Data System (ADS)

The purpose of the present paper was to report the recent results, obtained in development of digital pulse processing mathematics for prompt fission neutron (PFN) investigation using twin ionization chamber (TIC) along with fast neutron time-of-flight detector (ND). Due to well known ambiguities in literature (see refs. [4, 6, 9 and 11]), concerning a pulse induction on TIC electrodes by FF ionization, we first presented detailed mathematical analysis of fission fragment (FF) signal formation on TIC anode. The analysis was done using Ramo-Shockley theorem, which gives relation between charged particle motion between TIC electrodes and so called weighting potential. Weighting potential was calculated by direct numerical solution of Laplace equation (neglecting space charge) for the TIC geometry and ionization, caused by FF. Formulae for grid inefficiency (GI) correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and discussed.

Zeynalova, O.; Zeynalov, Sh.; Nazarenko, M.; Hambsch, F.-J.; Oberstedt, S.

2011-11-01

366

Nuclear Fission Investigation with Twin Ionization Chamber  

SciTech Connect

The purpose of the present paper was to report the recent results, obtained in development of digital pulse processing mathematics for prompt fission neutron (PFN) investigation using twin ionization chamber (TIC) along with fast neutron time-of-flight detector (ND). Due to well known ambiguities in literature (see refs. [4, 6, 9 and 11]), concerning a pulse induction on TIC electrodes by FF ionization, we first presented detailed mathematical analysis of fission fragment (FF) signal formation on TIC anode. The analysis was done using Ramo-Shockley theorem, which gives relation between charged particle motion between TIC electrodes and so called weighting potential. Weighting potential was calculated by direct numerical solution of Laplace equation (neglecting space charge) for the TIC geometry and ionization, caused by FF. Formulae for grid inefficiency (GI) correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and discussed.

Zeynalova, O.; Zeynalov, Sh. [JINR-Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Nazarenko, M. [Moscow State Institute of Radioengineering and Automation, 78 Vernadski Avenue, 119454 Moscow (Russian Federation); Hambsch, F.-J.; Oberstedt, S. [EC-JRC Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel (Belgium)

2011-11-29

367

Plant exposure laboratory and chambers. Volume 1  

SciTech Connect

The research is to learn the factors that control plant uptake, translocation, and metabolism of anthropogenic organic chemicals. Understanding these processes is essential to predict food contamination and environmental damage from various agricultural and industrial pollutants. Contamination of plants is only one component, but since plants are the fulcrum upon which all nourishment systems depend, understanding the ways they become contaminated is critical to prudent production, transportation, and use of organic chemicals. These efforts to identify the controlling mechanisms of these phenomena require an understanding of the physiological parameters of the plants during uptake and translocation of the extraneous chemicals. Since the chemicals of interest are toxic and studies generally include /sup 14/C as a label for monitoring chemical kinetics, containment is an important criterion. The paper describes the laboratory and support system, the exposure chambers, the computer system, and the plant hydroponic nursery built to accomplish this research.

McFarlane, C.; Pfleeger, T.

1986-01-01

368

Performance of the TOPAZ time projection chamber  

SciTech Connect

The TOPAZ detector has began taking data at the TRISTAN e/sup +/e/sup -/ colliding beam ring in May 1987. The major detector elements including the time projection chamber (TPC) have been working quite satisfactorily. The authors report here the performance of TPC based on real e/sup +/e/sup -/ events and cosmic ray events. They measure spatial resolution of sigma/sub xy/ = 185..mu..m and sigma/sub z/ = 335..mu..m, momentum resolution of sigma/sub PT//P/sub T/ = ..sqrt..(1.5P/sub T/)/sup 2/ + (1.6)/sup 2%/ and dE/dx resolution of 4.6%.

Shirahashi, A.; Aihara, H.; Itoh, R.; Kamae, T.; Kusuki, N.; Tanaka, M.; Fujii, H.; Fujii, K.; Ikeda, H.; Iwasaki, H.

1988-02-01

369

Fabrication of GRCop-84 Rocket Thrust Chambers  

NASA Technical Reports Server (NTRS)

GRCop-84, a copper alloy, Cu-8 at% Cr-4 at% Nb developed at NASA Glenn Research Center for regenerative1y cooled rocket engine liners has excellent combinations of elevated temperature strength, creep resistance, thermal conductivity and low cycle fatigue. GRCop-84 is produced from pre-alloyed atomized powder and has been fabricated into plate, sheet and tube forms as well as near net shapes. Fabrication processes to produce demonstration rocket combustion chambers will be presented and includes powder production, extruding, rolling, forming, friction stir welding, and metal spinning. GRCop-84 has excellent workability and can be readily fabricated into complex components using conventional powder and wrought metallurgy processes. Rolling was examined in detail for process sensitivity at various levels of total reduction, rolling speed and rolling temperature representing extremes of commercial processing conditions. Results indicate that process conditions can range over reasonable levels without any negative impact to properties.

Loewenthal, William; Ellis, David

2006-01-01

370

Fabrication of GRCop-84 Rocket Thrust Chambers  

NASA Technical Reports Server (NTRS)

GRCop-84, a copper alloy, Cu-8 at% Cr-4 at% Nb developed at NASA Glenn Research Center for regeneratively cooled rocket engine liners has excellent combinations of elevated temperature strength, creep resistance, thermal conductivity and low cycle fatigue. GRCop-84 is produced from prealloyed atomized powder and has been fabricated into plate, sheet and tube forms as well as near net shapes. Fabrication processes to produce demonstration rocket combustion chambers will be presented and includes powder production, extruding, rolling, forming, friction stir welding, and metal spinning. GRCop-84 has excellent workability and can be readily fabricated into complex components using conventional powder and wrought metallurgy processes. Rolling was examined in detail for process sensitivity at various levels of total reduction, rolling speed and rolling temperature representing extremes of commercial processing conditions. Results indicate that process conditions can range over reasonable levels without any negative impact to properties.

Loewenthal, William S.; Ellis, David L.

2005-01-01

371

The Fission Time Projection Chamber Project  

NASA Astrophysics Data System (ADS)

New high-precision fission experiments have become a priority within the low-energy nuclear community. Modern sensitivity calculations have revealed unacceptable liabilities in some of the underlying fundamental nuclear data and have provided target accuracies for new measurements that are well beyond what can be delivered using current experimental technologies. A potential breakthrough in the precision barrier for these measurements is the deployment of a Time Projection Chamber (TPC). TPC detector systems were originally developed within the particle physics community and have played a central role in that field for nearly 25 years. A group of 6 universities and 3 national laboratories have undertaken the task of building the first TPC designed specifically for the purpose of measuring fission cross sections. In this talk, I will present the motivation for the fission TPC concept, a few details of the device and why we think an improvement on 50 years of fission experiments can be accomplished.

Hill, Tony

2009-10-01

372

Development of an optical digital ionization chamber  

SciTech Connect

We are developing a new device for optically detecting and imaging the track of a charged particle in a gas. The electrons in the particle track are made to oscillate rapidly by the application of an external, short-duration, high-voltage, RF electric field. The excited electrons produce additional ionization and electronic excitation of the gas molecules in their immediate vicinity, leading to copious light emission (fluorescence) from the selected gas, allowing the location of the electrons along the track to be determined. Two digital cameras simultaneously scan the emitted light across two perpendicular planes outside the chamber containing gas. The information thus obtained for a given track can be used to infer relevant quantities for microdosimetry and dosimetry, e.g., energy deposited, LET, and track structure in the gas. The design of such a device now being constructed and methods of obtaining the dosimetric data from the digital output will be described. 4 refs., 4 figs.

Turner, J.E.; Hunter, S.R.; Hamm, R.N.; Wright, H.A.; Hurst, G.S.; Gibson, W.A.

1988-01-01

373

Bubble Chambers for Experiments in Nuclear Astrophysics  

E-print Network

A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with gamma-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas tar...

DiGiovine, B; Holt, R J; Rehm, K E; Raut, R; Robinson, A; Sonnenschein, A; Rusev, G; Tonchev, A P; Ugalde, C

2015-01-01

374

Pseudoexfoliation material on posterior chamber intraocular lenses  

PubMed Central

The presence of pseudoexfoliation material on the surface of an intraocular lens (IOL) is a rare finding. We report a series of seven cases with different patterns of pseudoexfoliation material deposition on the posterior chamber IOLs, recognized 2–20 years after cataract surgery. Six patients had an IOL implanted in the capsular bag and one in the ciliary sulcus. Two patients had undergone posterior capsulotomy. Although the pathophysiological mechanisms and clinical significance of this finding remain unknown, the careful follow-up of pseudophakic patients with known or suspected pseudoexfoliation syndrome is essential to monitor the development or progression of glaucoma, since deposition of pseudoexfoliation material continues even after cataract surgery. PMID:25143707

da Rocha-Bastos, Ricardo António; Silva, Sérgio Estrela; Prézia, Flávio; Falcão-Reis, Fernando; Melo, António B

2014-01-01

375

Resistive Plate Chambers: electron transport and modeling  

NASA Astrophysics Data System (ADS)

We study the electron transport in gas mixtures used by Resistive Plate Chambers (RPCs) in high energy physics experiments at CERN. Calculations are performed using a multi term theory for solving the Boltzmann equation. We identify the effects induced by non-conservative nature of electron attachment, including attachment heating of electrons and negative differential conductivity (NDC). NDC was observed only in the bulk component of drift velocity. Using our Monte Carlo technique, we calculate the spatially resolved transport properties in order to investigate the origin of these effects. We also present our microscopic approach to modeling of RPCs which is based on Monte Carlo method. Calculated results for a timing RPC show good agreement with an analytical model and experimental data. Different cross section sets for electron scattering in C2H2F4 are used for comparison and analysis.

Bošnjakovi?, D.; Petrovi?, Z. Lj; Dujko, S.

2014-12-01

376

Phoenix Lowered into Thermal Vacuum Chamber  

NASA Technical Reports Server (NTRS)

NASA's Phoenix Mars Lander was lowered into a thermal vacuum chamber at Lockheed Martin Space Systems, Denver, in December 2006.

The spacecraft was folded in its aeroshell and underwent environmental testing that simulated the extreme conditions the spacecraft will see during its nine-and-a-half-month cruse to Mars.

The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

2007-01-01

377

FFTF (FAST FLUX TEST FACILITY) REACTOR CHARACTERIZATION PROGRAM ABSOLUTE FISSION RATE MEASUREMENTS  

SciTech Connect

Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

FULLER JL; GILLIAM DM; GRUNDL JA; RAWLINS JA; DAUGHTRY JW

1981-05-01

378

Neutron Flux Characterization of the Cold Beam PGAA-NIPS Facility at the Budapest Research Reactor  

NASA Astrophysics Data System (ADS)

Reliable flux characterization is essential for facilities using neutron beams. Hence, the NIPS station at the Budapest Research Reactor has recently been equipped with neutron-tomographic equipment. The beam can also be characterized by means of a large surface wire chamber and application of the time-of-flight method. The energy distribution was measured at three horizontal positions with the surface wire chamber in pinhole geometry, while the spatial inhomogeneity was determined by means of our new neutron-tomographic equipment.

Belgya, T.; Kis, Z.; Szentmiklósi, L.

2014-05-01

379

High-Aspect-Ratio Cooling Channel Concept Tested in Lewis' Rocket Engine Test Facility  

NASA Technical Reports Server (NTRS)

Rocket combustion chamber walls are exposed to the high-temperature environment caused by the combustion of propellants. Even with the walls actively cooled by the fuel, the hot gases can deteriorate the walls severely and limit any possibility for reusing the combustion chamber. For many years, the NASA Lewis Research Center has performed subscale investigations of potential improved cooling concepts to extend the life and reliability of the combustion chamber. Results from previous subscale tests have shown that, by increasing the coolant channel height-to-width aspect ratio, the rocket combustion chamber hot gas side wall temperature can be reduced by as much as 28 percent, without an increase in the coolant pressure drop. Recently, a series of experiments were completed in Lewis' Rocket Engine Test Facility (RETF) to validate the benefits of high aspect ratio cooling channels with a high-pressure, contoured rocket combustion chamber.

1995-01-01

380

TSUNAMI analysis of National Ignition Facility 2-D gas dynamics phenomenon  

SciTech Connect

The tests in the chamber of National Ignition Facility will involve complex multi-dimensional dynamics phenomena. Many safety concerns relate to the ablation of the chamber material and the re-condensation of it. The x-ray induced ablation can vaporize surfaces of internal structures. The deposition of the ablated mass to the laser optics can cause significant damage to the laser optics. This study presents a typical analysis of the ablation from the target positioner in the NIF chamber with the TSUNAMI two-dimensional gas dynamics code. Results reveal that the geometry of target positioner has strong influence to the vapor mass amount and distribution over the chamber wall. The analysis done here shows that it is possible to perform parametric study for different NIF chamber design configurations.

Chen, X.M.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States); Tobin, M.T. [Lawrence Livermore National Lab., CA (United States)

1994-11-01

381

Dielectric liquid ionization chambers for detecting fast neutrons  

E-print Network

Three ionization chambers with different geometries have been constructed and filled with dielectric liquids for detection of fast neutrons. The three dielectric liquids studied were Tetramethylsilane (TMS), Tetramethylpentane ...

Boyd, Erin M

2008-01-01

382

Electrodeless drift chambers with 50-cm drift distance  

SciTech Connect

The electrodeless drift-chamber technique is potentially very useful in applications requiring the drifting of ionization in gas over long distances in narrow channels. Chamber construction is simple and cheap; the technique is well suited to very large detectors operating in low-rate environments. Prototype tests on planar chambers reveal excellent drifting characteristics after the initial charging, but show a substantial degradation of pulse height from cosmic rays over a two-week period. The loss of efficiency appears to be caused by excess charge buildup on the dielectric surfaces of the chamber. Several solutions are suggested.

Ayres, D.S.; Price, L.E.

1982-08-01

383

Explosive Containment Chamber Vulnerability to Chemical Munition Fragment Impact  

SciTech Connect

Scenarios in which the explosive burster charge in a chemical munition accidentally detonates inside demilitarization containment chambers are analyzed. The vulnerability of an inner Auxiliary Pressure Vessel and the primary Explosive Containment Chamber to impact by fragments from the largest explosive charge expected to be placed in these chambers (M426, 8 inch, chemical, 7 lbs Comp B) is evaluated. Numerical (CTH) and empirical (ConWep) codes are used to characterize the munition fragments, and assess the consequences of their impact and penetration on the walls of these vessels. Both pristine and corroded configurations of the munition have been considered, with and without liquid agent fill. When the munition burster charge detonates, munition case fragments impact and perforate the Auxiliary Pressure Vessel wall, resulting in extensive breakup of this inner chamber and the formation of additional fragments. These residual munition case and Auxiliary Pressure Vessel fragments have sufficient mass and velocity to crater the Explosive Containment Chamber inner wall layer, with accompanying localized permanent deformation (bulging) of both the inner and outer chamber walls. The integrity of the Explosive Containment Chamber was retained under all of the APV / munition configurations considered in this study, with no evidence that primary (munition) or secondary (munition and Auxiliary Pressure Vessel) fragments will perforate the inner chamber wall. Limited analyses of munition detonation without the Auxiliary Pressure Vessel present indicate that some munition span fragments could form under those conditions that have sufficient mass and velocity to perforate the inner wall of the Explosive Containment Chamber.

Benham, R.A.; Fischer, S.H.; Kipp, M.E.; Martinez, R.R.

1999-02-01

384

Cooling of rocket thrust chambers with liquid oxygen  

NASA Technical Reports Server (NTRS)

Rocket engines using high pressure liquid oxygen (LOX) and kerosene (RP-1) as the propellants have been considered for future launch vehicle propulsion. Generally, in regeneratively cooled engines, the fuel is used to cool the combustion chamber. However, hydrocarbons such as RP-1 are limited in their cooling capability at high temperatures and pressures. Therefore, LOX is being considered as an alternative coolant. However, there has been concern as to the effect on the integrity of the chamber liner if oxygen leaks into the combustion zone through fatigue cracks that may develop between the cooling passages and the hot-gas side wall. To address this concern, an investigation was previously conducted with simulated fatigue cracks upstream of the thrust chamber throat. When these chambers were tested, an unexpected melting in the throat region developed which was not in line with the simulated fatigue cracks. The current experimental program was conducted in order to determine the cause for the failure in the earlier thrust chambers and to further investigate the effects of cracks in the thrust chamber liner upstream of the throat. The thrust chambers were tested at oxygen-to-fuel mixture ratios from 1.5 to 2.86 at a nominal chamber pressure of 8.6 MPa. As a result of the test series, the reason for the failure occurring in the earlier work was determined to be injector anomalies. The LOX leaking through the simulated fatigue cracks did not affect the integrity of the chambers.

Armstrong, Elizabeth S.; Schlumberger, Julie A.

1990-01-01

385

Liquid Oxygen Cooling of Hydrocarbon Fueled Rocket Thrust Chambers  

NASA Technical Reports Server (NTRS)

Rocket engines using liquid oxygen (LOX) and hydrocarbon fuel as the propellants are being given serious consideration for future launch vehicle propulsion. Normally, the fuel is used to regeneratively cool the combustion chamber. However, hydrocarbons such as RP-1 are limited in their cooling capability. Another possibility for the coolant is the liquid oxygen. Combustion chambers previously tested with LOX and RP-1 as propellants and LOX as the collant demonstrated the feasibility of using liquid oxygen as a coolant up to a chamber pressure of 13.8 MPa (2000 psia). However, there was concern as to the effect on the integrity of the chamber liner if oxygen leaks into the combustion zone through fatigue cracks that may develop between the cooling passages and the hot gas side wall. In order to study this effect, chambers were fabricated with slots machined upstream of the throat between the cooling passage wall and the hot gas side wall to simulate cracks. The chambers were tested at a nominal chamber pressure of 8.6 MPa (1247 psia) over a range of mixture ratios from 1.9 to 3.1 using liquid oxygen as the coolant. The results of the testing showed that the leaking LOX did not have a deleterious effect on the chambers in the region of the slots. However, there was unexplained melting in the throat region of both chambers, but not in line with the slots.

Armstrong, Elizabeth S.

1989-01-01

386

Determination of molecular contamination performance for space chamber tests  

NASA Technical Reports Server (NTRS)

The limitations of chamber tests with regard to the molecular contamination of a spacecraft undergoing vacuum test were examined. The molecular flow conditions existing in the chamber and the parameters dictating the degree of contamination were analyzed. Equations and graphs were developed to show the fraction of molecules returning to the spacecraft out of those emitted and to show other chamber flow parameters as a function of chamber and spacecraft surface molecular pumping and geometric configuration. Type and location of instruments required to measure the outgassing, the degree of contamination, and the returning flows are also discussed.

Scialdone, J. J.

1973-01-01

387

Main Chamber and Preburner Injector Technology  

NASA Technical Reports Server (NTRS)

This document reports the experimental and analytical research carried out at the Penn State Propulsion Engineering Research Center in support of NASA's plan to develop advanced technologies for future single stage to orbit (SSTO) propulsion systems. The focus of the work is on understanding specific technical issues related to bi-propellant and tri-propellant thrusters. The experiments concentrate on both cold flow demonstrations and hot-fire uni-element tests to demonstrate concepts that can be incorporated into hardware design and development. The analysis is CFD-based and is intended to support the design and interpretation of the experiments and to extrapolate findings to full-scale designs. The research is divided into five main categories that impact various SSTO development scenarios. The first category focuses on RP-1/gaseous hydrogen (GH2)/gaseous oxygen (GO2) tri-propellant combustion with specific emphasis on understanding the benefits of hydrogen addition to RP-1/oxygen combustion and in developing innovative injector technology. The second category investigates liquid oxygen (LOX)/GH2 combustion at main chamber near stoichiometric conditions to improve understanding of existing LOX/GH2 rocket systems. The third and fourth categories investigate the technical issues related with oxidizer-rich and fuel-rich propulsive concepts, issues that are necessary for developing the full-flow engine cycle. Here, injector technology issues for both LOX/GH2 and LOX/RP-1 propellants are examined. The last category, also related to the full-flow engine cycle, examines injector technology needs for GO2/GH2 propellant combustion at near-stoichiometric conditions for main chamber application.

Santoro, Robert J.; Merkle, Charles L.

1999-01-01

388

The Joint Airlock Module is moved to the O&C vacuum chamber  

NASA Technical Reports Server (NTRS)

The Joint Airlock Module swings into position near the top of the Operations and Checkout Building to move toward the vacuum chamber at right. Workers alongside the chamber watch the airlock's progress. The airlock is being tested for leaks. The module is the gateway from which crew members aboard the International Space Station (ISS) will enter and exit the 470-ton orbiting research facility. The airlock is a critical element of the ISS because of design differences between American and Russian spacesuits. The Joint Airlock Module provides a chamber where astronauts from every nation can suit up for space walks to conduct maintenance and construction work or to do science experiments outside the Station. The Space Shuttle Atlantis will carry the airlock to orbit on mission STS-104, the 10th International Space Station flight, currently targeted for liftoff in May 2001. The Shuttle crew will secure the airlock to the right side of Unity, the American-built connecting node that currently comprises one-third of the current Space Station, along with the Russian modules Zarya and Zvezda.

2000-01-01

389

Calibration of a new chamber using GUPIX software package for PIXE analysis  

NASA Astrophysics Data System (ADS)

A new chamber has been designed and constructed for the second beam line at the Lund Nuclear Microprobe facility, Sweden. The aim with the chamber is to perform standardized analyses with most of the nuclear analytical techniques (proton induced X-ray emission, particle elastic scattering analysis, proton induced gamma emission, nuclear reaction analysis, etc.) with a millimetre size beam. The beam line and chamber constructions are described in this paper. The possibility to run samples in batch, and the special arrangement developed for this is described. A mass calibration of the PIXE set-up has been done with MicroMatter thin film standards and other thick standards. The spectra were acquired with CAMAC based data acquisition system with Kmax interfacing software. The GUPIX software package recently installed in our laboratory has been used to process the PIXE spectra and the results are compared with the certified values. For standardization the instrumental constant H (solid angle and correction factor) is determined relying completely on the GUPIX data base (cross-sections, fluorescence and Coster-Kronig probabilities, stopping powers and attenuation coefficients) for a large set of elements. These H values are saved inside the GUPIX library, to be used in future analysis.

Shariff, Asad; Bülow, Karin; Elfman, Mikael; Kristiansson, Per; Malmqvist, Klas; Pallon, Jan

2002-04-01

390

Smog chamber studies on the influence of diesel exhaust on photosmog formation  

NASA Astrophysics Data System (ADS)

In an outdoor smog chamber, volatile organic compounds (VOC)/NO x/air mixtures were irradiated by natural sunlight in the presence and the absence of diesel exhaust. The VOC mixture contained n-butane, ethene and toluene with a fixed mixing ratio. Diesel exhaust was generated by a diesel engine mounted on a motor test bed directly at the chamber facility. Five different diesel fuel formulations were used. Each experiment was carried out under similar initial conditions for VOC and NO x. In the presence of diesel exhaust, the formation of ozone was significantly increased. Simulation of the experiments performed using a chemical box model yielded good agreement between measured and calculated concentrations for all chamber runs. The increase in ozone formation observed on addition of diesel exhaust was mainly caused by the exhaust concentrations of nitrous acid and formaldehyde, which serve as strong radical sources in the initial phase of each exhaust experiment. A sensitivity analysis showed that the photooxidant formation was not dependent on the formulation of the diesel fuel used. The different ozone formation rates observed for the single exhaust experiments were clearly caused by deviations in initial reactant concentrations as well as photolysis conditions.

Geiger, Harald; Kleffmann, Jörg; Wiesen, Peter

391

Experimental Analysis of Gaseous Chambers for the ATLAS Muon sub-detector Upgrade R&D  

NASA Astrophysics Data System (ADS)

CERN, the world's largest particle accelerator facility, has begun its ambitious Large Hadron Collider (LHC) program which is and will remain as the world energy frontier until at least 2030. ATLAS, one of the LHC experiments designed to search for new physics, has been taking data for two years. ATLAS has been investigating the necessary changes to its sub-detectors to withstand much higher instantaneous luminosity and to operate after 3000 fb-1 of integrated data. The goal is to achieve the same or better performance (spatial resolution, etc.) despite the large increase in event rate and final integrated dose. The current ATLAS Muon sub-detector will not be able to handle the increased luminosity of a factor of ten. This makes it necessary to replace the current muon sub-detector by possible new gaseous chambers that push their performance to limits never tested before. This talk will focus on the different lab experiments performed at CERN during the summers of 2011 and 2012, including functional uniformity results of a new ``T-series'' chamber design developed by the ATLAS Muon detector upgrade R&D team. As a result, a new visual mapping design was developed by the author that enabled an easier way to find anomalies in the chambers. This work has been presented to ATLAS Weekly Micromegas Meeting's 6 times during the summers of 2011 and 2012.

Angulo, Emmanuel

2012-11-01

392

Design of the target area for the National Ignition Facility  

NASA Astrophysics Data System (ADS)

The preliminary design of the target area for the National Ignition Facility has been completed. The target area is required to meet a challenging set of engineering system design requirements and user needs. The target area must provide the appropriate conditions before, during, and after each shot. The repeated introduction of large amounts of laser energy into the chamber and subsequent target emissions represent new design challenges for ICF facility design. Prior to each shot, the target area must provide the required target illumination, target chamber vacuum, diagnostics, and optically stable structures. During the shot, the impact of the target emissions on the target chamber, diagnostics, and optical elements is minimized and the workers and public are protected from excessive prompt radiation doses. After the shot, residual radioactivation is managed to allow the required accessibility. Diagnostic data is retrieved, operations and maintenance activities are conducted, and the facility is ready for the next shot. The target area subsystems include the target chamber, target positioner, structural systems, target diagnostics, environmental systems, and the final optics assembly. The engineering design of the major elements of the target area requires a unique combination of precision engineering, structural analysis, opto-mechanical design, random vibration suppression, thermal stability, materials engineering, robotics, and optical cleanliness. The facility has been designed to conduct both x-ray driven targets and to be converted at a later date for direct drive experiments. The NIF has been configured to provide a wide range of experimental environments for the anticipated user groups of the facility. The design status of the major elements of the target area is described.

Foley, Richard J.; Karpenko, Victor P.; Adams, Chris H.; Patel, C. S.; Pittenger, L. C.; Lee, F. Dean; Reitz, T. C.; Hibbard, Wilthea J.; Horton, W. R.; Trummer, David J.; Tobin, Michael T.; McDonald, Anthony E.; Wavrik, R. W.; Pittman, P. C.

1997-12-01

393

Quantifying the "chamber effect" in CO2 flux measurements  

NASA Astrophysics Data System (ADS)

The significance of aquatic CO2 emissions has received attention in recent years. For example annual aquatic emissions in the Amazon basin have been estimated as 500 Mt of carbon1. Methods for determining the flux rates include eddy covariance flux tower measurements, flux estimates calculated from partial pressure of CO2 (pCO2) in water and the use floating flux chambers connected to an infra-red gas analyser. The flux chamber method is often used because it is portable, cheaper and allows smaller scale measurements. It is also a direct method and hence avoids problems related to the estimation of the gas transfer coefficient that is required when fluxes are calculated from pCO2. However, the use of a floating chamber may influence the flux measurements obtained. The chamber shields the water underneath from effects of wind which could lead to lower flux estimates. Wind increases the flux rate by i) causing waves which increase the surface area for efflux, and ii) removing CO2 build up above the water surface, hence maintaining a higher concentration gradient. Many floating chambers have an underwater extension of the chamber below the float to ensure better seal to water surface and to prevent any ingress of atmospheric air when waves rock the chamber. This extension may cause additional turbulence in flowing water and hence lead to overestimation of flux rates. Some groups have also used a small fan in the chamber headspace to ensure thorough mixing of air in the chamber. This may create turbulence inside the chamber which could increase the flux rate. Here we present results on the effects of different chamber designs on the detected flux rates. 1Richey et al. 2002. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2. Nature 416: 617-620.

Vihermaa, Leena; Childs, Amy; Long, Hazel; Waldron, Susan

2014-05-01

394

The U.S. Lab is placed in vacuum chamber for leak test  

NASA Technical Reports Server (NTRS)

Workers in the Operations and Checkout Building check the placement of the lid on the vacuum chamber containing the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

2000-01-01

395

The U.S. Lab placed in vacuum chamber for leak test  

NASA Technical Reports Server (NTRS)

In the Operations and Checkout Building, the U.S. Lab, a component of the International Space Station, is lowered into a three-story vacuum chamber. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

2000-01-01

396

The U.S. Lab is placed in vacuum chamber for leak test  

NASA Technical Reports Server (NTRS)

- An overhead crane moves the lid over the vacuum chamber containing the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

2000-01-01

397

The U.S. Lab is placed in vacuum chamber for leak test  

NASA Technical Reports Server (NTRS)

A worker in the Operations and Checkout Building checks the placement of the lid on the vacuum chamber containing the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

2000-01-01

398

Active Target-Time Projection Chambers for Reactions Induced by Rare Isotope Beams: Physics and Technology  

NASA Astrophysics Data System (ADS)

Weakly bound nuclear systems can be considered to represent a good testing-ground of our understanding of non-perturbative quantum systems. Great progress in experimental sensitivity has been attained by increase in rare isotope beam intensities and by the development of new high efficiency detectors. It is now possible to study reactions leading to bound and unbound states in systems with very unbalanced neutron to proton ratios. Application of Active Target-Time Projection Chambers to this domain of physics will be illustrated by experiments performed with existing detectors. The NSCL is developing an Active Target-Time Projection Chamber (AT-TPC) to be used to study reactions induced by rare isotope beams at the National Superconducting Cyclotron Facility (NSCL) and at the future Facility for Rare Isotope Beams (FRIB). The AT-TPC counter gas acts as both a target and detector, allowing investigations of fusion, isobaric analog states, cluster structure of light nuclei and transfer reactions to be conducted without significant loss in resolution due to the thickness of the target. The high efficiency and low threshold of the AT-TPC will allow investigations of fission barriers and giant resonances with fast fragmentation rare isotope beams. This detector type needs typically a large number of electronic channels (order of magnitude 10,000) and a high speed DAQ. A reduced size prototype detector with prototype electronics has been realized and used in several experiments. A short description of other detectors of this type under development will be given.

Mittig, Wolfgang

2013-04-01

399

EVALUATING THE TOXICITY OF URBAN PATTERNS OF OXIDANT GASES. 1. AN AUTOMATED CHRONIC GASEOUS ANIMAL INHALATION EXPOSURE FACILITY  

EPA Science Inventory

An automated animal inhalation exposure facility was designed to conduct chronic exposures of rodents to gaseous pollutants. The facility consisted of 3 walk-in chambers with modular cages to allow for exposure of up to a maximum of 480 mice or 240 adult rats. Critical parameters...

400

The Nozzle Acoustic Test Rig: an Acoustic and Aerodynamic Free-jet Facility  

NASA Technical Reports Server (NTRS)

The nozzle acoustic test rig (NATR) was built at NASA Lewis Research Center to support the High Speed Research Program. The facility is capable of measuring the acoustic and aerodynamic performance of aircraft engine nozzle concepts. Trade-off studies are conducted to compare performance and noise during simulated low-speed flight and takeoff. Located inside an acoustically treated dome with a 62-ft radius, the NATR is a free-jet that has a 53-in. diameter and is driven by an air ejector. This ejector is operated with 125 lb/s of compressed air, at 125 psig, to achieve 375 lb/s at Mach 0.3. Acoustic and aerodynamic data are collected from test nozzles mounted in the free-jet flow. The dome serves to protect the surrounding community from high noise levels generated by the nozzles, and to provide an anechoic environment for acoustic measurements. Information presented in this report summarizes free-jet performance, fluid support systems, and data acquisition capabilities of the NATR.

Castner, Raymond S.

1994-01-01

401

THE CARBON DIOXIDE LEAKAGE FROM CHAMBERS MEASURED USING SULFUR HEXAFLUORIDE  

EPA Science Inventory

In plant chamber studies, if Co2 leaking from a chamber is not quantified, it can lead to an overestimate of assimilation rates and an underestimate of respiration rates: consequently, it is critical that Co2 leakage be determined. Sulfur Hexafluoride (SF6) was introduced into t...

402

The high-rate behavior of parallel mesh chambers  

Microsoft Academic Search

Gas counters made from parallel metallic wire meshes have been proposed by Charpak et al. (1978) long ago as a preamplifying stage to wire chambers and developed meanwhile by many workers. The concept led to very robust and versatile detectors, having evolved over time to include complex multistep structures. It is known that parallel geometry chambers can stand counting rates

I. Ivaniouchenkov; P. Fonte; V. Peskov; R. Ferreira-Marques; A. Policarpo

1998-01-01

403

U.S. Chamber Adds Business Viewpoint on Schools' Quality  

ERIC Educational Resources Information Center

With a new and highly critical report card offering a business perspective on the effectiveness of state education systems, the U.S. Chamber of Commerce is pushing what it sees as a prescription for more innovative, efficient, and better-performing schools. For the chamber, the grades and policy platform further a concerted new effort to shape…

Archer, Jeff

2007-01-01

404

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, John F. Kennedy Space Center, Florida. Drawing 68-K-L-11213, NASA KSC, March, 1971. DOOR LATCH MECHANISM & DOOR LATCHING RATCHET. Sheet 14 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

405

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Photocopy of drawing. ALTITUDE CHAMBERS ?L? & ?R? STRUCTURES. NASA, John F. Kennedy Space Center, Florida. Drawing 68-K-L-11213, NASA KSC, November, 1968. WORK PLATFORM DETAIL. Sheet 6 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

406

7. SEDIMENTATION CHAMBER AT 520', CONSTRUCTED 19371938, VIEWED FROM DOWNSTREAM. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. SEDIMENTATION CHAMBER AT 520', CONSTRUCTED 1937-1938, VIEWED FROM DOWNSTREAM. DEBRIS REMOVED FROM TOP PLANKS FOR CLARITY. ONE OF TWO SPILLWAYS SEEN AT RIGHT. FLUSH VALVE SEEN AT LOWER LEFT AND WRENCH FOR VALVES IS PROPPED AGAINST CHAMBER. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

407

NETWORKING FOR BUSINESS NORTH DUBLIN CHAMBER OF COMMERCE PRESENT  

E-print Network

NETWORKING FOR BUSINESS NORTH DUBLIN CHAMBER OF COMMERCE PRESENT The commitment to establish NAMA Dublin Chamber of Commerce is delighted to offer an opportunity to its members to discuss these issues with one of Ireland's leading financial economists, Dr. Valerio Poti from Dublin City University Business

Humphrys, Mark

408

EFFECTS OF OPEN-TOP CHAMBERS ON 'VALENCIA' ORANGE TREES  

EPA Science Inventory

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. ong-term ozone average concen...

409

Pressure chamber procedures for leaf water potential measurements of cotton  

Microsoft Academic Search

Measurement of leaf water potential (?l) with a pressure chamber is usually regarded as a reliable and practical field technique. However, recent evidence indicates that results depend on the measurement techniques employed. Field experiments were conducted to identify the magnitude and sources of error affecting pressure chamber measurements of ?l in cotton (Gossypium hirsutum L.) and to develop an accurate

M. Meron; D. W. Grimes; C. J. Phene; K. R. Davis

1987-01-01

410

TEMPERATURE AND HUMIDITY CONTROL IN INDIRECT CALORIMETER CHAMBERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A three chamber indirect calorimeter has been a part of the Environmental Laboratory at the U.S. Meat Animal Research Center (MARC) for over 25 yr (Nienaber and Maddy, 1987). Corrosion of the animal chamber and unreliable temperature control has forced major repairs. There is a strong demand for h...

411

Idea Bank: Chamber Music within the Large Ensemble  

ERIC Educational Resources Information Center

Many music educators incorporate chamber music in their ensemble programs--an excellent way to promote musical independence. However, they rarely think of the large ensemble as myriad chamber interactions. Rehearsals become more productive when greater responsibility for music-making is placed on the individual student. This article presents some…

Neidlinger, Erica

2011-01-01

412

Collaborative Composing in High School String Chamber Music Ensembles  

ERIC Educational Resources Information Center

The purpose of this study was to examine collaborative composing in high school string chamber music ensembles. Research questions included the following: (a) How do high school string instrumentalists in chamber music ensembles use verbal and musical forms of communication to collaboratively compose a piece of music? (b) How do selected variables…

Hopkins, Michael T.

2015-01-01

413

Heat pipe technology for advanced rocket thrust chambers  

NASA Technical Reports Server (NTRS)

The application of heat pipe technology to the design of rocket engine thrust chambers is discussed. Subjects presented are: (1) evaporator wick development, (2) specific heat pipe designs and test results, (3) injector design, fabrication, and cold flow testing, and (4) preliminary thrust chamber design.

Rousar, D. C.

1971-01-01

414

a Wire Tension Meter for the LHCb Muon Chambers  

Microsoft Academic Search

A wire tension meter has been developed for the multiwire chambers of the LHCb muon detector. The wire tension is deduced from its mechanical resonance frequency. In the LHCb muon chambers, the wires are electrically connected in group of 14, so that the wire excitation method based on the interaction between a current sent into a wire and an external

A. Buccheri; E. Dané; A. Frenkel; G. Martellotti; A. Medvedkov; A. Pelosi; G. Penso; D. Pinci; G. Pirozzi; M. Dwuznik; A. Kachtchouk; B. Schmidt; G. Felici; C. Forti; V. V. Kulikov; A. Nedosekin

2004-01-01

415

EVLA Memo # 78 EVLA Chamber Characterization confirms PCB RFI emissions  

E-print Network

measured from PCB's using the EVLA chamber. Once certified as correct, one can validate the designEVLA Memo # 78 EVLA Chamber Characterization confirms PCB RFI emissions Levels and module shielding that the telescope is designed to detect, a very high level of shielding (60-120 dB), for each RFI radiating

Groppi, Christopher

416

Heart chambers and whole heart segmentation techniques: review  

E-print Network

Heart chambers and whole heart segmentation techniques: review Dongwoo Kang Jonghye Woo Piotr J://electronicimaging.spiedigitallibrary.org/ on 01/15/2014 Terms of Use: http://spiedl.org/terms #12;Heart chambers and whole heart segmentation this problem. Recent studies employ sophisticated techniques using available cues from cardiac anatomy

Kuo, C.-C. "Jay"

417

Growth of Crop and Weeds in Growth Chambers and Outdoors  

Microsoft Academic Search

The early growth of spring barley (Hordeum ulgare L.), Brassica rapa L. ssp. oleifera (DC.) Metzger, Stellaria media (L.) Vill. and Viola arvensis Murray in growth chambers and in shading cages outdoors at different irradiance levels was compared. Leaf area and shoot dry weight were lower outdoors than in growth chambers at similar irradiance and temperature. A simulation model with

Kirsten Semb Tørresen; Lambertus A. P. Lotz

2000-01-01

418

Gas and aerosol wall losses in Teflon film smog chambers  

Microsoft Academic Search

Large smog chambers (approx.60 m³) constructed of FEP Teflon film are frequently used to study photochemistry and aerosol formation in model chemical systems. In a previous paper a theory for aerosol wall loss rates in Teflon film smog chambers was developed; predicted particle loss rates were in good agreement with measured rates. In the present paper, measurements of wall deposition

Peter H. McMurry; Daniel Grosjean

1985-01-01

419

Combustion chamber inlet manifold separates vapor from liquid  

NASA Technical Reports Server (NTRS)

Circular manifold with tangential orifices at the inner circumference provides for the vapor constituent of a vaporized cryogenic propellant to enter a rocket combustion chamber before the liquid constituent. The vapor is separated from the liquid by centrifugal action and precedes it into the chamber through carefully positioned orifices.

Baker, D. I.

1966-01-01

420

The Meditation Chamber : A Debriefing A. Fleming Seay  

E-print Network

The Meditation Chamber : A Debriefing A. Fleming Seay HCII Carnegie Mellon University afseay attendees experienced The Meditation Chamber. This immersive, bio-interactive environment was designed and meditation experience. During this sketch, the project's producers will discuss the design and implementation

Shaw, Chris

421

Liquid rocket engine fluid-cooled combustion chambers  

NASA Technical Reports Server (NTRS)

A monograph on the design and development of fluid cooled combustion chambers for liquid propellant rocket engines is presented. The subjects discussed are (1) regenerative cooling, (2) transpiration cooling, (3) film cooling, (4) structural analysis, (5) chamber reinforcement, and (6) operational problems.

1972-01-01

422

MEASUREMENT OF ORGANIC COMPOUND EMISSIONS USING SMALL TEST CHAMBERS  

EPA Science Inventory

Organic compounds emitted from a variety of indoor materials have been measured using small (166 L) environmental test chambers. The paper discusses: a) factors to be considered in small chamber testing; b) parameters to be controlled; c) the types of results obtained. The follow...

423

Exciting Internship at the American Arab Chamber of Commerce  

E-print Network

Exciting Internship at the American Arab Chamber of Commerce Take advantage of the opportunity@americanarab.com with the subject "Internship Opportunity." Include a brief statement on why you would like to work at the American Arab Chamber of Commerce, along with your availability. If you are looking for an internship to fulfill

Cinabro, David

424

Controls on the growth and eruption of large magma chambers  

NASA Astrophysics Data System (ADS)

What controls maximum magma chamber size? Deposits from flood basalts and ignimbrite flare-ups record multiple successive eruptions exceeding 1000 cubic kilometers, suggesting repeated assembly of reservoirs at least this large. Crustal heating through intrusion promotes viscous creep in country rocks, enabling stable growth of the magma chambers required for these eruptions. Numerical simulations show that melt influx rate, depth in the geotherm, and crustal composition exert primary control on chamber growth. But we find that fundamental size limits are imposed by the concentration of deviatoric stresses from the free surface, and chamber failure may be ultimately determined by the strength of crustal rocks. We focus on shallow caldera-forming magma chambers, motivated by the observed distribution of collapse calderas and their deposits on Earth, Mars and Io to study generic controls on chamber size. We develop a numerical model of coupled magma chamber deformation and conduit flow to simulate the coupled fluid and solid mechanics of caldera-forming eruptions. Crustal yield strength is the most important factor determining collapse, with roof aspect ratio and evolving rheology of magma in the chamber also important. We suggest that the largest silicic eruptions require country rocks with yield strength in excess of 100 MPa, which may evolve through thermal annealing of crust by intrusions. We use caldera size distributions to estimate the elastic strength of crust on Earth, Mars and Io.

Karlstrom, L.; Manga, M.; Rudolph, M. L.

2011-12-01

425

Disequilbrium plagioclase in Icelandic magma chambers  

NASA Astrophysics Data System (ADS)

The Austurhorn intrusive complex of southeast Iceland represents the exhumed roots of a ~6 Ma central volcano. A modally layered gabbro occupies the central part of the complex. The outer part is dominated by granophyre which frequently carries pillow- or sheet-like enclaves of basalt, interpreted to reflect mafic magma intruded into a molten rhyolitic magma chamber. Some of the basaltic pillows are highly plagioclase-phyric (20-30%) and carry macrocrysts with cores that are more primitive (An85-75) than overgrowth rims and groundmass grains (An67-43), indicating disequilibrium with the host melt. The layered gabbro comprises more than 800 m of cpx + plag ± ol ± Fe-Ti oxide cumulates and can be divided into at least 8 macrorhythmic units formed by repeated injections of mafic magma. Two distinct populations of high- and low-An plagioclase crystals have also been identified in the gabbro. The high-An grains are typically 2-4 mm, prismatic to tabular in shape and have bytownite cores (An87-69) abruptly zoned to labradorite rims (An65-55). The low-An grains (An69-55) are smaller (1-2 mm), typically lath-shaped and weakly zoned (?An ? 7 mol.%). Microdrilling followed by TIMS Sr isotope analyses of high- and low-An plagioclase grains indicate that the rims of the high-An grains (87Sr/86Sr = 0.70337-0.70340) are in isotopic equilibrium with the low-An grains (0.70338). The cores of the high-An grains, however, are generally more radiogenic (0.70342-0.70344) than coexisting rims, indicating a xenocrystic origin. We suggest that the high-An plagioclase macrocrysts of the basalt enclaves and the layered gabbro are two of kind and grew in a deeper, more primitive magma chamber. The macrocrysts were entrained by genetically unrelated magmas and were carried into the Austurhorn plumbing system during magma recharge events. The low-An grains, on the other hand, are interpreted to record in situ growth.

Thórarinsson, Sigurjón B.; Tegner, Christian; Waight, Tod E.

2014-05-01

426

A mechanical mode-stirred reverberation chamber with chaotic geometry  

E-print Network

A previous research on multivariate approach to the calculation of reverberation chamber correlation matrices is used to calculate the number of independent positions in a mode-stirred reverberation chamber. Anomalies and counterintuitive behavior are observed in terms of number of correlated matrix elements with respect to increasing frequency. This is ascribed to the regular geometry forming the baseline cavity (screened room) of a reverberation chamber, responsible for localizing energy and preserving regular modes (bouncing ball modes). Smooth wall deformations are introduced in order to create underlying Lyapunov instability of rays and then destroy survived regular modes. Numerical full-wave simulations are performed for a reverberation chamber with corner hemispheres and (off-)center wall spherical caps. Field sampling is performed by moving a mechanical carousel stirrer. It is found that wave-chaos inspired baseline geometries improve chamber performances in terms of lowest usable frequencies and number of independent cavity realizations of mechanical stirrers.

Gabriele Gradoni; Franco Moglie; Valter Mariani Primiani

2014-07-06

427

Potassium Rankine cycle vapor chamber (heat pipe) radiator study  

NASA Technical Reports Server (NTRS)

A structurally integrated vapor chamber fin (heat pipe) radiator is defined and evaluated as a potential candidate for rejecting waste heat from the potassium Rankine cycle powerplant. Several vapor chamber fin geometries, using stainless steel construction, are evaluated and an optimum is selected. A comparison is made with an operationally equivalent conduction fin radiator. Both radiators employ NaK-78 in the primary coolant loop. In addition, the Vapor Chamber Fin (VCF) radiator utilizes sodium in the vapor chambers. Preliminary designs are developed for the conduction fin and VCF concepts. Performance tests on a single vapor chamber were conducted to verify the VCF design. A comparison shows the conduction fin radiator easier to fabricate, but heavier in weight, particularly as meteoroid protection requirements become more stringent. While the analysis was performed assuming the potassium Rankine cycle powerplant, the results are equally applicable to any system radiating heat to space in the 900 to 1400 F temperature range.

Gerrels, E. E.; Killen, R. E.

1971-01-01

428

Space Power Facility Readiness for Space Station Power System Testing  

NASA Technical Reports Server (NTRS)

This document provides information which shows that the NASA Lewis Research Center's Space Power Facility (SPF) will be ready to execute the Space Station electric power system thermal vacuum chamber testing. The SPF is located at LeRC West (formerly the Plum Brook Station), Sandusky, Ohio. The SPF is the largest space environmental chamber in the world, having an inside horizontal diameter of 100 ft. and an inside height at the top of the hemisphere of 122 ft. The vacuum system can achieve a pressure lower than 1 x 10(exp -5) Torr. The cryoshroud, cooled by gaseous nitrogen, can reach a temperature of -250 F, and is 80 ft. long x 40 ft. wide x 22 ft. high. There is access to the chamber through two 50 ft. x 50 ft. doors. Each door opens into an assembly area about 150 ft. long x 70 ft. wide x 80 ft. high. Other available facilities are offices, shop area, data acquisition system with 930 pairs of hard lines, 7 megawatts of power to chamber, 245K gal. liquid nitrogen storage, cooling tower, natural gas, service air, and cranes up to 25 tons.

Smith, Roger L.

1995-01-01

429

Ionization Chamber for Prompt Fission Neutron Investigations  

NASA Astrophysics Data System (ADS)

In this work we report recent achievements in design of twin back-to-back ionization chamber (TIC) for fission fragment (FF) mass and kinetic energy measurement. Correlated FF kinetic energies, their masses and the angle of FF in respect to the axes in 3D Cartesian coordinates can be determined from analysis of the heights and shapes of the pulses induced by the fission fragments on the anodes of TIC. Anodes of TIC were designed as consisting of isolated strips each having independent electronic circuitry and special multi-channel pulse processing apparatus. Mathematical formulae provided for FF angles measured in respect to the coordinate axes. It was shown how the point of fission fragments origin on the target plane may be determined using the same measured data. The last feature made the TIC a rather powerful tool for prompt fission neutron (PFN) emission investigation in event-by-event analysis of individual fission reactions from non- point fissile source. Position sensitive neutron induced fission detector for neutron-imaging applications with both thermal and low energy neutrons was found as another possible implementation of the designed TIC.

Zeynalov, Sh.; Zeynalova, O.; Hambsch, F.-J.; Sedyshev, P.; Shvetsov, V.

430

Resistive plate chambers in positron emission tomography  

NASA Astrophysics Data System (ADS)

Resistive plate chambers (RPC) were originally deployed for high energy physics. Realizing how their properties match the needs of nuclear medicine, a LIP team proposed applying RPCs to both preclinical and clinical positron emission tomography (RPC-PET). We show a large-area RPC-PET simulated scanner covering an axial length of 2.4m —slightly superior to the height of the human body— allowing for whole-body, single-bed RPC-PET acquisitions. Simulations following NEMA (National Electrical Manufacturers Association, USA) protocols yield a system sensitivity at least one order of magnitude larger than present-day, commercial PET systems. Reconstruction of whole-body simulated data is feasible by using a dedicated, direct time-of-flight-based algorithm implemented onto an ordered subsets estimation maximization parallelized strategy. Whole-body RPC-PET patient images following the injection of only 2mCi of 18-fluorodesoxyglucose (FDG) are expected to be ready 7 minutes after the 6 minutes necessary for data acquisition. This compares to the 10-20mCi FDG presently injected for a PET scan, and to the uncomfortable 20-30minutes necessary for its data acquisition. In the preclinical field, two fully instrumented detector heads have been assembled aiming at a four-head-based, small-animal RPC-PET system. Images of a disk-shaped and a needle-like 22Na source show unprecedented sub-millimeter spatial resolution.

Crespo, Paulo; Blanco, Alberto; Couceiro, Miguel; Ferreira, Nuno C.; Lopes, Luís; Martins, Paulo; Ferreira Marques, Rui; Fonte, Paulo

2013-07-01

431

Design of microfission chamber for ITER operations  

SciTech Connect

Microfission chambers (MFCs) are one of the most important diagnostics for measuring neutron source strength in ITER. Using MFCs for high-power operations (fusion power of 100 kW-1 GW) and for low-power operations (<100 kW) in combination is one way to fulfill the target measurement requirements of ITER. The MFCs for high-power operations will be installed behind blanket modules in both the upper and lower outboard regions of the vacuum vessel so as to be insensitive to changes in the position of the plasma. For low-power operations, one possible location of MFCs is inside the equatorial (EQ) port. The effect of streaming neutrons and of changes in the position of the plasma on the responses of MFCs is estimated based on a neutron Monte Carlo calculation using the MCNP Version 5 code. Results suggest that the effect of streaming neutrons should be taken into account if the MFCs for high-power operations are installed closer than 20 cm to the gap between blanket modules. It has also been found for MFCs of low-power operations that the averaged output of the MFCs installed at the top and bottom of the EQ port is sensitive to horizontal plasma shifts but not to vertical shifts. This finding suggests that corrections based on the position of the plasma center will be needed for the absolute measurement of neutron source strength.

Ishikawa, Masao; Kondoh, Takashi; Nishitani, Takeo; Kusama, Yoshinori [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Ibaraki 311-0193 (Japan)

2008-10-15

432

Resistive Plate Chamber Efficiency & Rate Capability Analysis  

NASA Astrophysics Data System (ADS)

Bakelite-based resistive plate chambers (RPCs) are particle detectors commonly used in muon trigger systems for high-energy physics experiments. Bakelite RPCs combine fast response, sufficient position resolution and low cost, and they can be operated at instantaneous background rates up to approximately 1.5 kHz/cm^2. Current and future collider experiments will demand operation of trigger RPCs under background rates higher than what is currently achieved. The rate capability is related to the bulk and surface conductivities of the Bakelite material used for the plates bordering the active gas volume in the RPCs. At the LHC and RHIC, these surfaces are coated with linseed oil, which lowers the surface resistivity of the Bakelite, which, to a point, improves the rate capability of the detectors. We have doped our own plates with various concentrations of carbon black. Over the past year we have tested RPCs with Bakelite plates of different resistivity using cosmic ray muons and radioactive Fe55 sources to emulate different levels of background in the detector. Results on the RPC efficiencies at different background rates and for different Bakelite coatings will be presented.

Candocia, Max

2012-10-01

433

Chemistry of radiation damage to wire chambers  

SciTech Connect

Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF{sub 4}/iC{sub 4}H{sub 10} gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF{sub 4}-rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF{sub 4}, acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF{sub 4}/iC{sub 4}H{sub 10} gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C{sub 2}H{sub 6}. Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl{sub 3}F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds.

Wise, J.

1992-08-01

434

Vacuum chamber for ion manipulation device  

SciTech Connect

An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area. A predetermined number of pairs of surfaces are disposed in one or more chambers, forming a multiple-layer ion mobility cyclotron device.

Chen, Tsung-Chi; Tang, Keqi; Ibrahim, Yehia M; Smith, Richard D; Anderson, Gordon A; Baker, Erin M

2014-12-09

435

R3B time projection chamber  

NASA Astrophysics Data System (ADS)

Within the international FAIR project, the R3B collaboration (Reaction studies with Radioactive Relativistic beams) will be in charge of the physics program with secondary beams of energy between 200 and 1500MeV per nucleon. Central to the R3B set-up will be a large-aperture superconducting magnet under construction at CEA-Saclay. An international collaboration has been formed to work on the design of a large time-projection chamber (TPC) to be installed behind this magnet to cover the full phase-space of the charged fragments produced in the target. Within this collaboration, tests of detector prototypes were performed with the heavy-ions beams at GSI Darmstadt. These prototypes were equipped with a gaseous Micromegas detector. Two amplification technologies were tested, either conventional or resistive Micromegas and two construction concepts, bulk-Micromegas or micro-meshes screwed on the PCB. We will present the results of the last beam and the 1m TPC station which will be dedicated to make tests using the real drift distance and compare the performances of micromegas and GEM.

Legou, P.

2012-07-01

436

Characterizing particle resuspension from mattresses: chamber study.  

PubMed

People spend approximately one-third of their lives sleeping, where they can be exposed to a myriad of particle-bound biological agents and chemical pollutants that originate within mattresses and bedding, including allergens, fungal spores, bacteria, and particle-phase semi-volatile organic compounds. Full-scale particle resuspension experiments were conducted in an environmental chamber, where volunteers performed a prescribed movement routine on an artificially seeded mattress. Human movements in bed, such as rolling from the prone to supine position, were found to resuspend settled particles, leading to elevations in airborne particle concentrations. Resuspension rates were estimated for the size fractions of 1-2 ?m, 2-3 ?m, 3-5 ?m, 5-10 ?m, and 10-20 ?m, and were in the range of 10(-3) to 10(1)  h(-1) . Particle size had the most significant impact on the resuspension rate, whereas dust loading, volunteer body mass, and ventilation rate had a much smaller impact. Resuspension increased with the intensity of a movement, as characterized by surface vibrations, and decreased with repeated movement routines. Inhalation exposure was characterized with the intake fraction metric. Intake fractions increased as the particle size and ventilation rate decreased and ranged from 10(2) to 10(4) inhaled particles per million resuspended, demonstrating that a significant fraction of released particles can be inhaled by sleeping occupants. PMID:25077669

Boor, B E; Spilak, M P; Corsi, R L; Novoselac, A

2014-07-31

437

Resistive plate chamber for thermal neutron detection  

NASA Astrophysics Data System (ADS)

The possibility to detect thermal neutrons with single gap resistive plate chambers (RPCs) has been investigated. The development of the detector has been performed in the frame of the detection and imaging of antipersonnel land-mine by neutron back-scattering (DIAMINE) European Project for humanitarian de-mining. The RPCs are simple devices widely used in many particles physics experiments as trigger detectors because of their fast response and good spatial resolution. The RPC detects the charged particles generated by neutrons via the (n,?) reaction on boron. A 10B 4C thin coating on the inner surface of one RPC electrode is used as thermal neutron converter. A simulation study has been performed to optimize the converter thickness and the RPC working parameters. Tests on converter samples have been performed with a thermalized 252Cf source in order to evaluate the conversion efficiency. A first detector prototype has been realized and tested with cosmic rays and thermal neutrons. Results of simulation and experimental measurements of conversion efficiency, together with the description of the RPC prototype, are presented.

Arnaldi, R.; Chiavassa, E.; Colla, A.; Cortese, P.; Dellacasa, G.; De Marco, N.; Ferretti, A.; Gallio, M.; Musso, A.; Oppedisano, C.; Piccotti, A.; Poggio, F.; Scalas, E.; Scomparin, E.; Sigaudo, F.; Vercellin, E.

2004-01-01

438

Beam Test Data Analysis of the Beam Test Data Analysis of the JLCCDC baby Chamber JLCCDC baby Chamber  

Microsoft Academic Search

Studying the higgs boson needs a high resolution tracker. The baby chamber was fabricated with the same cell structure as the current design of the central drift chamber of the Joint Linear Collider. Its performance is studied by looking at the wire efficiency, spatial resolution and twotrack separation capability using an analysis software package already incorporated into the Joint Linear

H. Goo; D. Arogancia; J. Magallanes; A. Bacal; K. Fujii

439

30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.  

...MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.305 Access to drying chambers, hot gas inlet chambers...tight sealing access doors which shall remain latched during dryer operation to prevent the emission of coal dust and the loss...

2014-07-01

440

30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.  

Code of Federal Regulations, 2013 CFR

...MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.305 Access to drying chambers, hot gas inlet chambers...tight sealing access doors which shall remain latched during dryer operation to prevent the emission of coal dust and the loss...

2013-07-01

441

30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.  

Code of Federal Regulations, 2012 CFR

...MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.305 Access to drying chambers, hot gas inlet chambers...tight sealing access doors which shall remain latched during dryer operation to prevent the emission of coal dust and the loss...

2012-07-01

442

30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.  

Code of Federal Regulations, 2011 CFR

...MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.305 Access to drying chambers, hot gas inlet chambers...tight sealing access doors which shall remain latched during dryer operation to prevent the emission of coal dust and the loss...

2011-07-01

443

30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.  

Code of Federal Regulations, 2010 CFR

...MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Thermal Dryers § 77.305 Access to drying chambers, hot gas inlet chambers...tight sealing access doors which shall remain latched during dryer operation to prevent the emission of coal dust and the loss...

2010-07-01

444

Design and commissioning experience of SALT facility  

NASA Astrophysics Data System (ADS)

The commissioning experience of the facility for SALT is compared to the results of the analysis done during the design. A false steel floor incorporating forced ventilation that extends around the telescope azimuth pier is installed to prevent heat radiating from the concrete surfaces on nights when the ambient temperature drops to below room temperature. An infrared scan was done on this floor to verify that no heat is radiated into the telescope chamber from either the concrete or the warmer rooms underneath. The SALT site is windy all year round, and in order to utilize this natural resource and get better ventilation, adjustable louvers are used for natural ventilation. The control system automatically adjusts the louver openings depending on the wind speed and relative direction of the dome opening to achieve enough air changes during wind still nights. The louvers are throttled to limit windshake on the structure on windy nights. Results of the computational fluid dynamic analysis (CFD) and actual measurements are presented showing adequate temperature distribution at low wind speeds. The correlation between the CFD and actual measurements are discussed, with reference to the surface and air temperatures in the telescope chamber under different ambient conditions. The telescope chamber and dome are built out of insulation panels to limit energy losses during the day when the chamber is air conditioned. It also ensures thermal inertia of the building is low and consequently allows its temperature to react quickly to changes in external ambient temperature. The correlation between the expected and actual capacity of the air conditioners are also discussed.

De Kock, Mariana; Venter, Sarel

2004-09-01

445

Confinement of ignition and yield on the National Ignition Facility  

SciTech Connect

The National Ignition Facility Target Area and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented. 16 refs., 3 figs.

Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T. [Lawrence Livermore National Lab., CA (United States)

1996-12-31

446

Design and evaluation of an aeroacoustic wind tunnel for measurement of axial flow fans.  

PubMed

An anechoic wind tunnel dedicated to fan self-noise studies has been designed and constructed at the von Karman Institute The multi-chamber, mass flow driven design allows for all fan performance characteristics, aerodynamic quantities (e.g., wake turbulence measurements), and acoustic properties to be assessed in the same facility with the same conditions. The acoustic chamber performance is assessed using the optimum reference method and found to be within the ISO 3745 standards down to 150 Hz for pure tone and broadband source mechanisms. The additional influence of installation effects of an aerodynamic inlet was found to create a scattered sound field only near the source location, while still providing good anechoic results at more distant sound pressure measurement positions. It was found to have inflow properties, span-wise uniformity, and low turbulence intensity, consistent with those desired for fan self-noise studies. PMID:22225036

Bilka, M; Anthoine, J; Schram, C

2011-12-01

447

Graph algorithms experimentation facility  

E-print Network

We provide a facility to experiment with graph algorithms. The facility is implemented as a client to XAGE, a software environment developed under the direction of Dr. James Abello. XAGE allows a user to visually animate algorithmic actions...

Sonom, Donald George

1994-01-01

448

Facility safety study  

NASA Technical Reports Server (NTRS)

The safety of NASA's in house microelectronics facility is addressed. Industrial health standards, facility emission control requirements, operation and safety checklists, and the disposal of epitaxial vent gas are considered.

1979-01-01

449

Cryogenic testing of Planck sorption cooler test facility  

NASA Technical Reports Server (NTRS)

A test facility has been upgraded in preparation for testing of two hydrogen sorption cryocoolers operating at 18/20 K. these sorption coolers are currently under development at the Jet Propulsion Laboratory. This work summarizes the scope of the test facility upgrade, including design for cryogenic cooling power delivery, system thermal management, insulation schemes, and data acquisition techniques. Ground support equipment for the sorption coolers, structural features of the test chamber, and the vacuum system involved for system testing will also be described in detail.

Zhang, B.; Pearson, D.; Borders, J.; Franklin, B.; Prina, M.; Hardy, J.; Crumb, D.

2004-01-01

450

A Heated Tube Facility for Rocket Coolant Channel Research  

NASA Technical Reports Server (NTRS)

The capabilities of a heated tube facility used for testing rocket engine coolant channels at the NASA Lewis Research Center are presented. The facility uses high current, low voltage power supplies to resistively heat a test section to outer wall temperatures as high as 730 C (1350 F). Liquid or gaseous nitrogen, gaseous helium, or combustible liquids can be used as the test section coolant. The test section is enclosed in a vacuum chamber to minimize heat loss to the surrounding system. Test section geometry, size, and material; coolant properties; and heating levels can be varied to generate heat transfer and coolant performance data bases.

Green, James M.; Pease, Gary M.; Meyer, Michael L.

1995-01-01

451

THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY The Radiological Research Accelerator Facility  

E-print Network

THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY 1 The Radiological Research Accelerator Facility for Radiological Research (CRR). Using the mi- crobeam facility, 10% of the cells were irradiated through

452

Overview of the National Ignition Facility  

SciTech Connect

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory will be the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. NIF is a 192 beam Nd-glass laser facility that will produce 1.8 MJ, 500 TW of ultraviolet light making it over fifty times more energetic than present ICF facilities. The NIF Project began in 1995 and is scheduled for completion in 2009. Ignition experiments on NIF, which will use tritium, are scheduled to begin in 2010. Tritium will arrive at the facility in individual target assemblies. The assemblies will be mounted to the Cryogenic TARget POSitioner (TARPOS), which provides the cryogenic cooling systems necessary to complete the formation of the ignition target's fuel ice layer. It also provides the positioning system that transports and holds the target at the center of the NIF chamber during a shot. After a shot, unburned tritium will be captured by the cryopumps. Upon regeneration, the cryopump effluent will be directed to the Tritium Processing System, part of NIF's. Personnel and Environmental Protection Systems. These systems also include, local contamination control systems, area and stack tritium monitoring systems, a decontamination area, and waste packaging and characterization capability. This equipment will be used along with standard contamination control practices to manage the tritium hazard to workers and to limit releases to the environment to negligibly small amounts.

Moses, E

2007-08-30

453

Overview of the national ignition facility  

SciTech Connect

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory will be the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. NIF is a 192 beam Nd-glass laser facility that will produce 1.8 MJ, 500 TW of ultraviolet light making it over fifty times more energetic than present ICF facilities. The NIF Project began in 1995 and is scheduled for completion in 2009. Ignition experiments on NIF, which will use tritium, are scheduled to begin in 2010. Tritium will arrive at the facility in individual target assemblies. The assemblies will be mounted to the Cryogenic Target Positioner (TARPOS), which provides the cryogenic cooling systems necessary to complete the formation of the ignition target's fuel ice layer. It also provides the positioning system that transports and holds the target at the center of the NIF chamber during a shot. After a shot, unburned tritium will be captured by the cryopumps. Upon regeneration, the cryopump effluent will be directed to the Tritium Processing System, part of NIF's. Personnel and Environmental Protection Systems. These systems also include, local contamination control systems, area and stack tritium monitoring systems, a decontamination area, and waste packaging and characterization capability. This equipment will be used along with standard contamination control practices to manage the tritium hazard to workers and to limit releases to the environment to negligibly small amounts. (authors)

Moses, E. I. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States)

2008-07-15

454

Fourth-generation plasma immersion ion implantation and deposition facility for hybrid surface modification layer fabrication.  

PubMed

The fourth-generation plasma immersion ion implantation and deposition (PIIID) facility for hybrid and batch treatment was built in our laboratory recently. Comparing with our previous PIIID facilities, several novel designs are utilized. Two multicathode pulsed cathodic arc plasma sources are fixed on the chamber wall symmetrically, which can increase the steady working time from 6 h (the single cathode source in our previous facilities) to about 18 h. Meanwhile, the inner diameter of the pulsed cathodic arc plasma source is increased from the previous 80 to 209 mm, thus, large area metal plasma can be obtained by the source. Instead of the simple sample holder in our previous facility, a complex revolution-rotation sample holder composed of 24 shafts, which can rotate around its axis and adjust its position through revolving around the center axis of the vacuum chamber, is fixed in the center of the vacuum chamber. In addition, one magnetron sputtering source is set on the chamber wall instead of the top cover in the previous facility. Because of the above characteristic, the PIIID hybrid process involving ion implantation, vacuum arc, and magnetron sputtering deposition can be acquired without breaking vacuum. In addition, the PIIID batch treatment of cylinderlike components can be finished by installing these components on the rotating shafts on the sample holder. PMID:18315292

Wang, Langping; Huang, Lei; Xie, Zhiwen; Wang, Xiaofeng; Tang, Baoyin

2008-02-01

455

A User's Guide for the Spacecraft Fire Safety Facility  

NASA Technical Reports Server (NTRS)

The Spacecraft Fire Safety Facility (SFSF) is a test facility that can be flown on NASA's reduced gravity aircraft to perform various types of combustion experiments under a variety of experimental conditions. To date, this facility has flown numerous times on the aircraft and has been used to perform experiments ranging from an examination of the effects transient depressurization on combustion, to ignition and flame spread. A list of pubfications/presentations based on experiments performed in the SFSF is included in the reference section. This facility consists of five main subsystems: combustion chamber, sample holders, gas flow system, imaging system, and the data acquisition/control system. Each of these subsystems will be reviewed in more detail. These subsystems provide the experiment operator with the ability to monitor and/or control numerous experimental parameters.

Goldmeer, Jeffrey S.

2000-01-01

456

Facilities maintenance handbook  

NASA Technical Reports Server (NTRS)

This handbook is a guide for facilities maintenance managers. Its objective is to set minimum facilities maintenance standards. It also provides recommendations on how to meet the standards to ensure that NASA maintains its facilities in a manner that protects and preserves its investment in the facilities in a cost-effective manner while safely and efficiently performing its mission. This handbook implements NMI 8831.1, which states NASA facilities maintenance policy and assigns organizational responsibilities for the management of facilities maintenance activities on all properties under NASA jurisdiction. It is a reference for facilities maintenance managers, not a step-by-step procedural manual. Because of the differences in NASA Field Installation organizations, this handbook does not assume or recommend a typical facilities maintenance organization. Instead, it uses a systems approach to describe the functions that should be included in any facilities maintenance management system, regardless of its organizational structure. For documents referenced in the handbook, the most recent version of the documents is applicable. This handbook is divided into three parts: Part 1 specifies common definitions and facilities maintenance requirements and amplifies the policy requirements contained in NMI 8831. 1; Part 2 provides guidance on how to meet the requirements of Part 1, containing recommendations only; Part 3 contains general facilities maintenance information. One objective of this handbook is to fix commonality of facilities maintenance definitions among the Centers. This will permit the application of uniform measures of facilities conditions, of the relationship between current replacement value and maintenance resources required, and of the backlog of deferred facilities maintenance. The utilization of facilities maintenance system functions will allow the Centers to quantitatively define maintenance objectives in common terms, prepare work plans, and develop management information in order to statistically identify and analyze variances from those plans. It will also add credibility to the NASA facilities maintenance budgeting process. The key to a successful maintenance program is the understanding and support of the senior Center managers.

1991-01-01

457

Complete fabrication of target experimental chamber and implement initial target diagnostics to be used for the first target experiments in NDCX-1  

SciTech Connect

The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) has completed the fabrication of a new experimental target chamber facility for future Warm Dense Matter (WDM) experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. This achievement provides to the HIFS-VNL unique and state-of-the-art experimental capabilities in preparation for the planned target heating experiments using intense heavy ion beams.

Bieniosek, F.M.; Bieniosek, F.M.; Dickinson, M.R.; Henestroza, E.; Katayanagi, T.; Jung, J.Y.; Lee, C.W.; Leitner, M.; Ni, P.; Roy, P.; Seidl, P.; Waldron, W.; Welch, D.

2008-06-09

458

Performance of Several Combustion Chambers Designed for Aircraft Oil Engines  

NASA Technical Reports Server (NTRS)

Several investigations have been made on single-cylinder test engines to determine the performance characteristics of four types of combustion chambers designed for aircraft oil engines. Two of the combustion chambers studied were bulb-type precombustion chambers, the connecting orifice of one having been designed to produce high turbulence by tangential air flow in both the precombustion chamber and the cylinder. The other two were integral combustion chambers, one being dome-shaped and the other pent-roof shaped. The injection systems used included cam and eccentric driven fuel pumps, and diaphragm and spring-loaded fuel-injection valves. A diaphragm type maximum cylinder pressure indicator was used in part of these investigations with which the cylinder pressures were controlled to definite valves. The performance of the engines when equipped with each of the combustion chambers is discussed. The best performance for the tests reported was obtained with a bulb-type combustion chamber designed to give a high degree of turbulence within the bulb and cylinder. (author)

Joachim, William F; Kemper, Carlton

1928-01-01

459

Gas and aerosol wall losses in Teflon film smog chambers  

SciTech Connect

Large smog chambers (approx.60 m/sup 3/) constructed of FEP Teflon film are frequently used to study photochemistry and aerosol formation in model chemical systems. In a previous paper a theory for aerosol wall loss rates in Teflon film smog chambers was developed; predicted particle loss rates were in good agreement with measured rates. In the present paper, measurements of wall deposition rates and the effects of wall losses on measurements of gas-to-particle conversion in smog chambers are discussed. Calculations indicate that a large fraction of the aerosol formed in several smog chamber experiments was on the chamber walls at the end of the experiment. Estimated values for particulate organic carbon yield for several precursor hydrocarbons increased by factors of 1.3-6.0 when wall deposition was taken into account. The theory is also extended to loss rates of gaseous species. Such loss rates are either limited by diffusion through a concentration boundary layer near the surface or by uptake at the surface. It is shown that for a typical 60-m/sup 3/ Teflon film smog chamber, gas loss rates are limited by surface reaction rates if mass accommodation coefficients are less than 6 x 10/sup -6/. It follows that previously reported loss rates of several gases in a chamber of this type were limited by surface reactions.

McMurry, P.H.; Grosjean, D.

1985-12-01

460

Autoignition Chamber for Remote Testing of Pyrotechnic Devices  

NASA Technical Reports Server (NTRS)

The autoignition chamber (AIC) performs by remotely heating pyrotechnic devices that can fit the inner diameter of the tube furnace. Two methods, a cold start or a hot start, can be used with this device in autoignition testing of pyrotechnics. A cold start means extending a pyrotechnic device into the cold autoignition chamber and then heating the device until autoignition occurs. A hot start means heating the autoignition chamber to a specified temperature, and then extending the device into a hot autoignition chamber until autoignition occurs. Personnel are remote from the chamber during the extension into the hot chamber. The autoignition chamber, a commercially produced tubular furnace, has a 230-V, single-phase, 60-Hz electrical supply, with a total power output of 2,400 W. It has a 6-in. (15.2-cm) inner diameter, a 12-in. (30.4-cm) outer diameter and a 12-in.- long (30.4-cm), single-zone, solid tubular furnace (element) capable of heating to temperatures up to 2,012 F (1,100 C) in air.

Harrington, Maureen L.; Steward, Gerald R.; Dartez, Toby W.

2009-01-01

461

Testing of triple-GEM chambers for CBM experiment at FAIR using self-triggered readout electronics  

NASA Astrophysics Data System (ADS)

Triple GEM chamber has been selected to be used for the muon detection system (MUCH) in the Compressed Baryonic Matter (CBM) experiment at the upcoming Facility for the Antiproton and Ion Research (FAIR). Two prototype triple-GEM chambers filled with the mixture of argon and CO2 gases in the ratio of 70:30 were made of small-size (10 cm×10 cm) single-mask GEM foils and read by a self-triggered readout ASIC called nXYTER have been tested with pion beams at CERN. The readout electronics records the arrival times of GEM hits and of corresponding coincidence trigger signals separately. The distribution of time difference between GEM hits and respective triggers shows a peak demonstrating the time correlation between GEM hits and the trigger. The width (?) of the time-correlation peak, which is related to the time resolution of the chamber, reduces with voltage approaching ?12 ns at ?VGEM of 335 V. Considering the hits inside the time-correlation peak to correspond to the beam trigger, the efficiency reaches a plateau at 95% at ?GEM above 330 V. For a readout plane segmented by 3 mm×3 mm pads, on an average 1.2 pads are fired per trigger for pion beams at the operating voltage. The chamber shows a gain of ?4000 at ?VGEM of 350 V.

Dubey, A. K.; Chattopadhyay, S.; Saini, J.; Singaraju, R.; Murthy, G. S. N.; Viyogi, Y. P.; Abuhoza, A.; Biswas, S.; Frankenfeld, U.; Hehner, J.; Kleipa, V.; Morhardt, Th.; Schmidt, C. J.; Schmidt, D. J.; Lymanets, A.; Schmidt, H. R.

2014-08-01

462

Outdoor smog chamber experiments: reactivity of methanol exhaust. Part 2. Quality assurance and data processing system description  

SciTech Connect

The report describes the Quality Assurance and Data Processing procedures and systems used at the UNC Outdoor Smog Chamber Facility. The primary product of research conducted at this facility is information in the form of measurements of reactants and products in photochemical systems and measurements of the critical parameters that influence the chemical transformations system. Generating useful data begins with understanding the goals of the project and the special needs and concerns of conducting a successful smog-chamber operation. The system components are designed to collect, transfer, process, and report accurate, high-resolution data without loss or distortion. The system components in the Quality Assurance and Data Processing system are: people, hardware, software, checklists, and data bases. Quality-assurance checks are made at every level of the program. Pressurized gas-tank and liquid mixtures were used to establish experimental conditions of HC assuring consistency throughout the program. Several NBS traceable standards and liquid injections into the chamber used for calibration have been intercompared and show good agreement.

Jeffries, H.E.; Sexton, K.G.; Kamens, R.M.; Holleman, M.S.

1985-09-01

463

Knowledge based facilities management  

Microsoft Academic Search

Purpose – Facilities management has inherited the understanding of how organisations work as value creators from various management models such as Porter's, where value is created through “primary” and “support” activities. The gap between the aspiration of strategic relevance and reality has prompted the facilities management profession to begin to address the question of whether facilities management is a legitimate

Zehra Waheed; Scott Fernie

2009-01-01

464

On Tracks in a Cloud Chamber  

NASA Astrophysics Data System (ADS)

It is an experimental fact that -decays produce in a cloud chamber at most one track (sequence of liquid droplets) and that this track points in a random direction. This seems to contradict the description of decay in Quantum Mechanics: according to Gamow a spherical wave is produced and moves radially according to Schrödinger's equation. It is as if the interaction with the supersaturated vapor turned the wave into a particle. The aim of this note is to place this effect in the context of Schrödinger's Quantum Mechanics. We shall see that the properties of the initial wave function suggest the introduction of a semiclassical formalism in which the -wave can be described as a collection of semiclassical (probability) wavelets; each of them interacts with an atom and forms an entangled state. The interaction can be regarded as a semiclassical inelastic scattering event. The measurement (of the position of the first droplet of the track) selects the wave function of one of the ions, with a probability given by Born's rule. This ion interacts with the atoms nearby leading to the formation of a droplet. One can reasonably assume that also the wavelet entangled with the selected ion has probability one to remain as part of the description of the system. The measurement process is therefore represented by a (non local) unitary operator. The (semiclassical) wavelet remains sharply localized on a classical path It is still a probability wave: it determines the probability that another atom be ionized. This probability is essentially zero unless the atom lies on . This gives the visible track.

Dell'Antonio, G. F.

2015-01-01

465

Modelling Contribution of Biogenic VOCs to New Particle Formation in the Jülich Plant Atmosphere Chamber  

NASA Astrophysics Data System (ADS)

Biogenic VOCs are substantially emitted from vegetation to atmosphere. The oxidation of BVOCs by OH, O3, and NO3 in air generating less volatile compounds may lead to the formation and growth of secondary organic aerosol, and thus presents a link to the vegetation, aerosol, and climate interaction system (Kulmala et al, 2004). Studies including field observations, laboratory experiments and modelling have improved our understanding on the connection between BVOCs and new particle formation mechanism in some extent (see e.g. Tunved et al., 2006; Mentel et al., 2009). Nevertheless, the exact formation process still remains uncertain, especially from the perspective of BVOC contributions. The purpose of this work is using the MALTE aerosol dynamics and air chemistry box model to investigate aerosol formation from reactions of direct tree emitted VOCs in the presence of ozone, UV light and artificial solar light in an atmospheric simulation chamber. This model employs up to date air chemical reactions, especially the VOC chemistry, which may potentially allow us to estimate the contribution of BVOCs to secondary aerosol formation, and further to quantify the influence of terpenes to the formation rate of new particles. Experiments were conducted in the plant chamber facility at Forschungszentrum Jülich, Germany (Jülich Plant Aerosol Atmosphere Chamber, JPAC). The detail regarding to the chamber facility has been written elsewhere (Mentel et al., 2009). During the experiments, sulphuric acid was measured by CIMS. VOC mixing ratios were measured by two GC-MS systems and PTR-MS. An Airmodus Particle size magnifier coupled with a TSI CPC and a PH-CPC were used to count the total particle number concentrations with a detection limit close to the expected size of formation of fresh nanoCN. A SMPS measured the particle size distribution. Several other parameters including ozone, CO2, NO, Temperature, RH, and flow rates were also measured. MALTE is a modular model to predict new aerosol formation in the lower troposphere, developed by Boy, et al. (2006). We first evaluate the modelled results with measurements, and further we investigate the influence of different order of magnitude of terpene mixing ratios, especially isoprene and monoterpenes to the most important parameter of new particles formation, i.e. the formation rate (J1). Also, the influence of varying organic source rates on the sulphuric acid concentration available for particle formation is discussed. M. Boy et al., (2006). Atmos. Chem. Phys., 6, 4499-4517. M. Kulmala et al., (2004). Atmos. Chem. Phys., 4, 557-562. P. Tunved et al., (2006). Science, 14, 261-263. Th. F. Mentel et al., (2009). Atmos. Chem. Phys., 9, 4387-4406.

Liao, L.; Boy, M.; Mogensen, D.; Mentel, T. F.; Kleist, E.; Kiendler-Scharr, A.; Tillman, R.; Kulmala, M. T.; Dal Maso, M.

2012-12-01

466

Optical imaging chamber for X-ray astronomy  

NASA Technical Reports Server (NTRS)

The light emitted by electron avalanches in a parallel plate chamber can be used to image the tracks of photoelectrons liberated by the interaction of an incident X-ray with the gas filling the chamber. The differing morphologies of photoelectron tracks and high-energy charged particle tracks can be used for background rejection. The initial direction (before scattering) of the liberated photoelectron also contains information about the polarization of the incident radiation. We have built a small test chamber with which we have imaged photoelectron tracks using an intensified CCD camera. Our results show that optical imaging could be used in a hard X-ray imaging polarimeter useful for astronomy.

Austin, Robert A.; Ramsey, Brian D.

1993-01-01

467

Turbine component cooling channel mesh with intersection chambers  

DOEpatents

A mesh (35) of cooling channels (35A, 35B) with an array of cooling channel intersections (42) in a wall (21, 22) of a turbine component. A mixing chamber (42A-C) at each intersection is wider (W1, W2)) than a width (W) of each of the cooling channels connected to the mixing chamber. The mixing chamber promotes swirl, and slows the coolant for more efficient and uniform cooling. A series of cooling meshes (M1, M2) may be separated by mixing manifolds (44), which may have film cooling holes (46) and/or coolant refresher holes (48).

Lee, Ching-Pang; Marra, John J

2014-05-06

468

Structurally compliant rocket engine combustion chamber: Experimental and analytical validation  

NASA Technical Reports Server (NTRS)

A new, structurally compliant rocket engine combustion chamber design has been validated through analysis and experiment. Subscale, tubular channel chambers have been cyclically tested and analytically evaluated. Cyclic lives were determined to have a potential for 1000 percent increase over those of rectangular channel designs, the current state of the art. Greater structural compliance in the circumferential direction gave rise to lower thermal strains during hot firing, resulting in lower thermal strain ratcheting and longer predicted fatigue lives. Thermal, structural, and durability analyses of the combustion chamber design, involving cyclic temperatures, strains, and low-cycle fatigue lives, have corroborated the experimental observations.

Jankovsky, Robert S.; Arya, Vinod K.; Kazaroff, John M.; Halford, Gary R.

1994-01-01